/*!
 * FullCalendar v2.8.0
 * Docs & License: http://fullcalendar.io/
 * (c) 2016 Adam Shaw
 */

(function (factory) {
    if (typeof define === 'function' && define.amd) {
        define(['jquery', 'moment'], factory);
    } else if (typeof exports === 'object') { // Node/CommonJS
        module.exports = factory(require('jquery'), require('moment'));
    } else {
        factory(jQuery, moment);
    }
})(function ($, moment) {

    ;
    ;

    var FC = $.fullCalendar = {
        version: "2.8.0",
        internalApiVersion: 4
    };
    var fcViews = FC.views = {};


    $.fn.fullCalendar = function (options) {
        var args = Array.prototype.slice.call(arguments, 1); // for a possible method call
        var res = this; // what this function will return (this jQuery object by default)

        this.each(function (i, _element) { // loop each DOM element involved
            var element = $(_element);
            var calendar = element.data('fullCalendar'); // get the existing calendar object (if any)
            var singleRes; // the returned value of this single method call

            // a method call
            if (typeof options === 'string') {
                if (calendar && $.isFunction(calendar[options])) {
                    singleRes = calendar[options].apply(calendar, args);
                    if (!i) {
                        res = singleRes; // record the first method call result
                    }
                    if (options === 'destroy') { // for the destroy method, must remove Calendar object data
                        element.removeData('fullCalendar');
                    }
                }
            }
            // a new calendar initialization
            else if (!calendar) { // don't initialize twice
                calendar = new Calendar(element, options);
                element.data('fullCalendar', calendar);
                calendar.render();
            }
        });

        return res;
    };


    var complexOptions = [// names of options that are objects whose properties should be combined
        'header',
        'buttonText',
        'buttonIcons',
        'themeButtonIcons'
    ];


// Merges an array of option objects into a single object
    function mergeOptions(optionObjs) {
        return mergeProps(optionObjs, complexOptions);
    }


// Given options specified for the calendar's constructor, massages any legacy options into a non-legacy form.
// Converts View-Option-Hashes into the View-Specific-Options format.
    function massageOverrides(input) {
        var overrides = {views: input.views || {}}; // the output. ensure a `views` hash
        var subObj;

        // iterate through all option override properties (except `views`)
        $.each(input, function (name, val) {
            if (name != 'views') {

                // could the value be a legacy View-Option-Hash?
                if (
                        $.isPlainObject(val) &&
                        !/(time|duration|interval)$/i.test(name) && // exclude duration options. might be given as objects
                        $.inArray(name, complexOptions) == -1 // complex options aren't allowed to be View-Option-Hashes
                        ) {
                    subObj = null;

                    // iterate through the properties of this possible View-Option-Hash value
                    $.each(val, function (subName, subVal) {

                        // is the property targeting a view?
                        if (/^(month|week|day|default|basic(Week|Day)?|agenda(Week|Day)?)$/.test(subName)) {
                            if (!overrides.views[subName]) { // ensure the view-target entry exists
                                overrides.views[subName] = {};
                            }
                            overrides.views[subName][name] = subVal; // record the value in the `views` object
                        } else { // a non-View-Option-Hash property
                            if (!subObj) {
                                subObj = {};
                            }
                            subObj[subName] = subVal; // accumulate these unrelated values for later
                        }
                    });

                    if (subObj) { // non-View-Option-Hash properties? transfer them as-is
                        overrides[name] = subObj;
                    }
                } else {
                    overrides[name] = val; // transfer normal options as-is
                }
            }
        });

        return overrides;
    }

    ;
    ;

// exports
    FC.intersectRanges = intersectRanges;
    FC.applyAll = applyAll;
    FC.debounce = debounce;
    FC.isInt = isInt;
    FC.htmlEscape = htmlEscape;
    FC.cssToStr = cssToStr;
    FC.proxy = proxy;
    FC.capitaliseFirstLetter = capitaliseFirstLetter;


    /* FullCalendar-specific DOM Utilities
     ----------------------------------------------------------------------------------------------------------------------*/


// Given the scrollbar widths of some other container, create borders/margins on rowEls in order to match the left
// and right space that was offset by the scrollbars. A 1-pixel border first, then margin beyond that.
    function compensateScroll(rowEls, scrollbarWidths) {
        if (scrollbarWidths.left) {
            rowEls.css({
                'border-left-width': 1,
                'margin-left': scrollbarWidths.left - 1
            });
        }
        if (scrollbarWidths.right) {
            rowEls.css({
                'border-right-width': 1,
                'margin-right': scrollbarWidths.right - 1
            });
        }
    }


// Undoes compensateScroll and restores all borders/margins
    function uncompensateScroll(rowEls) {
        rowEls.css({
            'margin-left': '',
            'margin-right': '',
            'border-left-width': '',
            'border-right-width': ''
        });
    }


// Make the mouse cursor express that an event is not allowed in the current area
    function disableCursor() {
        $('body').addClass('fc-not-allowed');
    }


// Returns the mouse cursor to its original look
    function enableCursor() {
        $('body').removeClass('fc-not-allowed');
    }


// Given a total available height to fill, have `els` (essentially child rows) expand to accomodate.
// By default, all elements that are shorter than the recommended height are expanded uniformly, not considering
// any other els that are already too tall. if `shouldRedistribute` is on, it considers these tall rows and 
// reduces the available height.
    function distributeHeight(els, availableHeight, shouldRedistribute) {

        // *FLOORING NOTE*: we floor in certain places because zoom can give inaccurate floating-point dimensions,
        // and it is better to be shorter than taller, to avoid creating unnecessary scrollbars.

        var minOffset1 = Math.floor(availableHeight / els.length); // for non-last element
        var minOffset2 = Math.floor(availableHeight - minOffset1 * (els.length - 1)); // for last element *FLOORING NOTE*
        var flexEls = []; // elements that are allowed to expand. array of DOM nodes
        var flexOffsets = []; // amount of vertical space it takes up
        var flexHeights = []; // actual css height
        var usedHeight = 0;

        undistributeHeight(els); // give all elements their natural height

        // find elements that are below the recommended height (expandable).
        // important to query for heights in a single first pass (to avoid reflow oscillation).
        els.each(function (i, el) {
            var minOffset = i === els.length - 1 ? minOffset2 : minOffset1;
            var naturalOffset = $(el).outerHeight(true);

            if (naturalOffset < minOffset) {
                flexEls.push(el);
                flexOffsets.push(naturalOffset);
                flexHeights.push($(el).height());
            } else {
                // this element stretches past recommended height (non-expandable). mark the space as occupied.
                usedHeight += naturalOffset;
            }
        });

        // readjust the recommended height to only consider the height available to non-maxed-out rows.
        if (shouldRedistribute) {
            availableHeight -= usedHeight;
            minOffset1 = Math.floor(availableHeight / flexEls.length);
            minOffset2 = Math.floor(availableHeight - minOffset1 * (flexEls.length - 1)); // *FLOORING NOTE*
        }

        // assign heights to all expandable elements
        $(flexEls).each(function (i, el) {
            var minOffset = i === flexEls.length - 1 ? minOffset2 : minOffset1;
            var naturalOffset = flexOffsets[i];
            var naturalHeight = flexHeights[i];
            var newHeight = minOffset - (naturalOffset - naturalHeight); // subtract the margin/padding

            if (naturalOffset < minOffset) { // we check this again because redistribution might have changed things
                $(el).height(newHeight);
            }
        });
    }


// Undoes distrubuteHeight, restoring all els to their natural height
    function undistributeHeight(els) {
        els.height('');
    }


// Given `els`, a jQuery set of <td> cells, find the cell with the largest natural width and set the widths of all the
// cells to be that width.
// PREREQUISITE: if you want a cell to take up width, it needs to have a single inner element w/ display:inline
    function matchCellWidths(els) {
        var maxInnerWidth = 0;

        els.find('> span').each(function (i, innerEl) {
            var innerWidth = $(innerEl).outerWidth();
            if (innerWidth > maxInnerWidth) {
                maxInnerWidth = innerWidth;
            }
        });

        maxInnerWidth++; // sometimes not accurate of width the text needs to stay on one line. insurance

        els.width(maxInnerWidth);

        return maxInnerWidth;
    }


// Given one element that resides inside another,
// Subtracts the height of the inner element from the outer element.
    function subtractInnerElHeight(outerEl, innerEl) {
        var both = outerEl.add(innerEl);
        var diff;

        // effin' IE8/9/10/11 sometimes returns 0 for dimensions. this weird hack was the only thing that worked
        both.css({
            position: 'relative', // cause a reflow, which will force fresh dimension recalculation
            left: -1 // ensure reflow in case the el was already relative. negative is less likely to cause new scroll
        });
        diff = outerEl.outerHeight() - innerEl.outerHeight(); // grab the dimensions
        both.css({position: '', left: ''}); // undo hack

        return diff;
    }


    /* Element Geom Utilities
     ----------------------------------------------------------------------------------------------------------------------*/

    FC.getOuterRect = getOuterRect;
    FC.getClientRect = getClientRect;
    FC.getContentRect = getContentRect;
    FC.getScrollbarWidths = getScrollbarWidths;


// borrowed from https://github.com/jquery/jquery-ui/blob/1.11.0/ui/core.js#L51
    function getScrollParent(el) {
        var position = el.css('position'),
                scrollParent = el.parents().filter(function () {
            var parent = $(this);
            return (/(auto|scroll)/).test(
                    parent.css('overflow') + parent.css('overflow-y') + parent.css('overflow-x')
                    );
        }).eq(0);

        return position === 'fixed' || !scrollParent.length ? $(el[0].ownerDocument || document) : scrollParent;
    }


// Queries the outer bounding area of a jQuery element.
// Returns a rectangle with absolute coordinates: left, right (exclusive), top, bottom (exclusive).
// Origin is optional.
    function getOuterRect(el, origin) {
        var offset = el.offset();
        var left = offset.left - (origin ? origin.left : 0);
        var top = offset.top - (origin ? origin.top : 0);

        return {
            left: left,
            right: left + el.outerWidth(),
            top: top,
            bottom: top + el.outerHeight()
        };
    }


// Queries the area within the margin/border/scrollbars of a jQuery element. Does not go within the padding.
// Returns a rectangle with absolute coordinates: left, right (exclusive), top, bottom (exclusive).
// Origin is optional.
// NOTE: should use clientLeft/clientTop, but very unreliable cross-browser.
    function getClientRect(el, origin) {
        var offset = el.offset();
        var scrollbarWidths = getScrollbarWidths(el);
        var left = offset.left + getCssFloat(el, 'border-left-width') + scrollbarWidths.left - (origin ? origin.left : 0);
        var top = offset.top + getCssFloat(el, 'border-top-width') + scrollbarWidths.top - (origin ? origin.top : 0);

        return {
            left: left,
            right: left + el[0].clientWidth, // clientWidth includes padding but NOT scrollbars
            top: top,
            bottom: top + el[0].clientHeight // clientHeight includes padding but NOT scrollbars
        };
    }


// Queries the area within the margin/border/padding of a jQuery element. Assumed not to have scrollbars.
// Returns a rectangle with absolute coordinates: left, right (exclusive), top, bottom (exclusive).
// Origin is optional.
    function getContentRect(el, origin) {
        var offset = el.offset(); // just outside of border, margin not included
        var left = offset.left + getCssFloat(el, 'border-left-width') + getCssFloat(el, 'padding-left') -
                (origin ? origin.left : 0);
        var top = offset.top + getCssFloat(el, 'border-top-width') + getCssFloat(el, 'padding-top') -
                (origin ? origin.top : 0);

        return {
            left: left,
            right: left + el.width(),
            top: top,
            bottom: top + el.height()
        };
    }


// Returns the computed left/right/top/bottom scrollbar widths for the given jQuery element.
// NOTE: should use clientLeft/clientTop, but very unreliable cross-browser.
    function getScrollbarWidths(el) {
        var leftRightWidth = el.innerWidth() - el[0].clientWidth; // the paddings cancel out, leaving the scrollbars
        var widths = {
            left: 0,
            right: 0,
            top: 0,
            bottom: el.innerHeight() - el[0].clientHeight // the paddings cancel out, leaving the bottom scrollbar
        };

        if (getIsLeftRtlScrollbars() && el.css('direction') == 'rtl') { // is the scrollbar on the left side?
            widths.left = leftRightWidth;
        } else {
            widths.right = leftRightWidth;
        }

        return widths;
    }


// Logic for determining if, when the element is right-to-left, the scrollbar appears on the left side

    var _isLeftRtlScrollbars = null;

    function getIsLeftRtlScrollbars() { // responsible for caching the computation
        if (_isLeftRtlScrollbars === null) {
            _isLeftRtlScrollbars = computeIsLeftRtlScrollbars();
        }
        return _isLeftRtlScrollbars;
    }

    function computeIsLeftRtlScrollbars() { // creates an offscreen test element, then removes it
        var el = $('<div><div/></div>')
                .css({
                    position: 'absolute',
                    top: -1000,
                    left: 0,
                    border: 0,
                    padding: 0,
                    overflow: 'scroll',
                    direction: 'rtl'
                })
                .appendTo('body');
        var innerEl = el.children();
        var res = innerEl.offset().left > el.offset().left; // is the inner div shifted to accommodate a left scrollbar?
        el.remove();
        return res;
    }


// Retrieves a jQuery element's computed CSS value as a floating-point number.
// If the queried value is non-numeric (ex: IE can return "medium" for border width), will just return zero.
    function getCssFloat(el, prop) {
        return parseFloat(el.css(prop)) || 0;
    }


    /* Mouse / Touch Utilities
     ----------------------------------------------------------------------------------------------------------------------*/

    FC.preventDefault = preventDefault;


// Returns a boolean whether this was a left mouse click and no ctrl key (which means right click on Mac)
    function isPrimaryMouseButton(ev) {
        return ev.which == 1 && !ev.ctrlKey;
    }


    function getEvX(ev) {
        if (ev.pageX !== undefined) {
            return ev.pageX;
        }
        var touches = ev.originalEvent.touches;
        if (touches) {
            return touches[0].pageX;
        }
    }


    function getEvY(ev) {
        if (ev.pageY !== undefined) {
            return ev.pageY;
        }
        var touches = ev.originalEvent.touches;
        if (touches) {
            return touches[0].pageY;
        }
    }


    function getEvIsTouch(ev) {
        return /^touch/.test(ev.type);
    }


    function preventSelection(el) {
        el.addClass('fc-unselectable')
                .on('selectstart', preventDefault);
    }


// Stops a mouse/touch event from doing it's native browser action
    function preventDefault(ev) {
        ev.preventDefault();
    }


// attach a handler to get called when ANY scroll action happens on the page.
// this was impossible to do with normal on/off because 'scroll' doesn't bubble.
// http://stackoverflow.com/a/32954565/96342
// returns `true` on success.
    function bindAnyScroll(handler) {
        if (window.addEventListener) {
            window.addEventListener('scroll', handler, true); // useCapture=true
            return true;
        }
        return false;
    }


// undoes bindAnyScroll. must pass in the original function.
// returns `true` on success.
    function unbindAnyScroll(handler) {
        if (window.removeEventListener) {
            window.removeEventListener('scroll', handler, true); // useCapture=true
            return true;
        }
        return false;
    }


    /* General Geometry Utils
     ----------------------------------------------------------------------------------------------------------------------*/

    FC.intersectRects = intersectRects;

// Returns a new rectangle that is the intersection of the two rectangles. If they don't intersect, returns false
    function intersectRects(rect1, rect2) {
        var res = {
            left: Math.max(rect1.left, rect2.left),
            right: Math.min(rect1.right, rect2.right),
            top: Math.max(rect1.top, rect2.top),
            bottom: Math.min(rect1.bottom, rect2.bottom)
        };

        if (res.left < res.right && res.top < res.bottom) {
            return res;
        }
        return false;
    }


// Returns a new point that will have been moved to reside within the given rectangle
    function constrainPoint(point, rect) {
        return {
            left: Math.min(Math.max(point.left, rect.left), rect.right),
            top: Math.min(Math.max(point.top, rect.top), rect.bottom)
        };
    }


// Returns a point that is the center of the given rectangle
    function getRectCenter(rect) {
        return {
            left: (rect.left + rect.right) / 2,
            top: (rect.top + rect.bottom) / 2
        };
    }


// Subtracts point2's coordinates from point1's coordinates, returning a delta
    function diffPoints(point1, point2) {
        return {
            left: point1.left - point2.left,
            top: point1.top - point2.top
        };
    }


    /* Object Ordering by Field
     ----------------------------------------------------------------------------------------------------------------------*/

    FC.parseFieldSpecs = parseFieldSpecs;
    FC.compareByFieldSpecs = compareByFieldSpecs;
    FC.compareByFieldSpec = compareByFieldSpec;
    FC.flexibleCompare = flexibleCompare;


    function parseFieldSpecs(input) {
        var specs = [];
        var tokens = [];
        var i, token;

        if (typeof input === 'string') {
            tokens = input.split(/\s*,\s*/);
        } else if (typeof input === 'function') {
            tokens = [input];
        } else if ($.isArray(input)) {
            tokens = input;
        }

        for (i = 0; i < tokens.length; i++) {
            token = tokens[i];

            if (typeof token === 'string') {
                specs.push(
                        token.charAt(0) == '-' ?
                        {field: token.substring(1), order: -1} :
                        {field: token, order: 1}
                );
            } else if (typeof token === 'function') {
                specs.push({func: token});
            }
        }

        return specs;
    }


    function compareByFieldSpecs(obj1, obj2, fieldSpecs) {
        var i;
        var cmp;

        for (i = 0; i < fieldSpecs.length; i++) {
            cmp = compareByFieldSpec(obj1, obj2, fieldSpecs[i]);
            if (cmp) {
                return cmp;
            }
        }

        return 0;
    }


    function compareByFieldSpec(obj1, obj2, fieldSpec) {
        if (fieldSpec.func) {
            return fieldSpec.func(obj1, obj2);
        }
        return flexibleCompare(obj1[fieldSpec.field], obj2[fieldSpec.field]) *
                (fieldSpec.order || 1);
    }


    function flexibleCompare(a, b) {
        if (!a && !b) {
            return 0;
        }
        if (b == null) {
            return -1;
        }
        if (a == null) {
            return 1;
        }
        if ($.type(a) === 'string' || $.type(b) === 'string') {
            return String(a).localeCompare(String(b));
        }
        return a - b;
    }


    /* FullCalendar-specific Misc Utilities
     ----------------------------------------------------------------------------------------------------------------------*/


// Computes the intersection of the two ranges. Returns undefined if no intersection.
// Expects all dates to be normalized to the same timezone beforehand.
// TODO: move to date section?
    function intersectRanges(subjectRange, constraintRange) {
        var subjectStart = subjectRange.start;
        var subjectEnd = subjectRange.end;
        var constraintStart = constraintRange.start;
        var constraintEnd = constraintRange.end;
        var segStart, segEnd;
        var isStart, isEnd;

        if (subjectEnd > constraintStart && subjectStart < constraintEnd) { // in bounds at all?

            if (subjectStart >= constraintStart) {
                segStart = subjectStart.clone();
                isStart = true;
            } else {
                segStart = constraintStart.clone();
                isStart = false;
            }

            if (subjectEnd <= constraintEnd) {
                segEnd = subjectEnd.clone();
                isEnd = true;
            } else {
                segEnd = constraintEnd.clone();
                isEnd = false;
            }

            return {
                start: segStart,
                end: segEnd,
                isStart: isStart,
                isEnd: isEnd
            };
        }
    }


    /* Date Utilities
     ----------------------------------------------------------------------------------------------------------------------*/

    FC.computeIntervalUnit = computeIntervalUnit;
    FC.divideRangeByDuration = divideRangeByDuration;
    FC.divideDurationByDuration = divideDurationByDuration;
    FC.multiplyDuration = multiplyDuration;
    FC.durationHasTime = durationHasTime;

    var dayIDs = ['sun', 'mon', 'tue', 'wed', 'thu', 'fri', 'sat'];
    var intervalUnits = ['year', 'month', 'week', 'day', 'hour', 'minute', 'second', 'millisecond'];


// Diffs the two moments into a Duration where full-days are recorded first, then the remaining time.
// Moments will have their timezones normalized.
    function diffDayTime(a, b) {
        return moment.duration({
            days: a.clone().stripTime().diff(b.clone().stripTime(), 'days'),
            ms: a.time() - b.time() // time-of-day from day start. disregards timezone
        });
    }


// Diffs the two moments via their start-of-day (regardless of timezone). Produces whole-day durations.
    function diffDay(a, b) {
        return moment.duration({
            days: a.clone().stripTime().diff(b.clone().stripTime(), 'days')
        });
    }


// Diffs two moments, producing a duration, made of a whole-unit-increment of the given unit. Uses rounding.
    function diffByUnit(a, b, unit) {
        return moment.duration(
                Math.round(a.diff(b, unit, true)), // returnFloat=true
                unit
                );
    }


// Computes the unit name of the largest whole-unit period of time.
// For example, 48 hours will be "days" whereas 49 hours will be "hours".
// Accepts start/end, a range object, or an original duration object.
    function computeIntervalUnit(start, end) {
        var i, unit;
        var val;

        for (i = 0; i < intervalUnits.length; i++) {
            unit = intervalUnits[i];
            val = computeRangeAs(unit, start, end);

            if (val >= 1 && isInt(val)) {
                break;
            }
        }

        return unit; // will be "milliseconds" if nothing else matches
    }


// Computes the number of units (like "hours") in the given range.
// Range can be a {start,end} object, separate start/end args, or a Duration.
// Results are based on Moment's .as() and .diff() methods, so results can depend on internal handling
// of month-diffing logic (which tends to vary from version to version).
    function computeRangeAs(unit, start, end) {

        if (end != null) { // given start, end
            return end.diff(start, unit, true);
        } else if (moment.isDuration(start)) { // given duration
            return start.as(unit);
        } else { // given { start, end } range object
            return start.end.diff(start.start, unit, true);
        }
    }


// Intelligently divides a range (specified by a start/end params) by a duration
    function divideRangeByDuration(start, end, dur) {
        var months;

        if (durationHasTime(dur)) {
            return (end - start) / dur;
        }
        months = dur.asMonths();
        if (Math.abs(months) >= 1 && isInt(months)) {
            return end.diff(start, 'months', true) / months;
        }
        return end.diff(start, 'days', true) / dur.asDays();
    }


// Intelligently divides one duration by another
    function divideDurationByDuration(dur1, dur2) {
        var months1, months2;

        if (durationHasTime(dur1) || durationHasTime(dur2)) {
            return dur1 / dur2;
        }
        months1 = dur1.asMonths();
        months2 = dur2.asMonths();
        if (
                Math.abs(months1) >= 1 && isInt(months1) &&
                Math.abs(months2) >= 1 && isInt(months2)
                ) {
            return months1 / months2;
        }
        return dur1.asDays() / dur2.asDays();
    }


// Intelligently multiplies a duration by a number
    function multiplyDuration(dur, n) {
        var months;

        if (durationHasTime(dur)) {
            return moment.duration(dur * n);
        }
        months = dur.asMonths();
        if (Math.abs(months) >= 1 && isInt(months)) {
            return moment.duration({months: months * n});
        }
        return moment.duration({days: dur.asDays() * n});
    }


// Returns a boolean about whether the given duration has any time parts (hours/minutes/seconds/ms)
    function durationHasTime(dur) {
        return Boolean(dur.hours() || dur.minutes() || dur.seconds() || dur.milliseconds());
    }


    function isNativeDate(input) {
        return  Object.prototype.toString.call(input) === '[object Date]' || input instanceof Date;
    }


// Returns a boolean about whether the given input is a time string, like "06:40:00" or "06:00"
    function isTimeString(str) {
        return /^\d+\:\d+(?:\:\d+\.?(?:\d{3})?)?$/.test(str);
    }


    /* Logging and Debug
     ----------------------------------------------------------------------------------------------------------------------*/

    FC.log = function () {
        var console = window.console;

        if (console && console.log) {
            return console.log.apply(console, arguments);
        }
    };

    FC.warn = function () {
        var console = window.console;

        if (console && console.warn) {
            return console.warn.apply(console, arguments);
        } else {
            return FC.log.apply(FC, arguments);
        }
    };


    /* General Utilities
     ----------------------------------------------------------------------------------------------------------------------*/

    var hasOwnPropMethod = {}.hasOwnProperty;


// Merges an array of objects into a single object.
// The second argument allows for an array of property names who's object values will be merged together.
    function mergeProps(propObjs, complexProps) {
        var dest = {};
        var i, name;
        var complexObjs;
        var j, val;
        var props;

        if (complexProps) {
            for (i = 0; i < complexProps.length; i++) {
                name = complexProps[i];
                complexObjs = [];

                // collect the trailing object values, stopping when a non-object is discovered
                for (j = propObjs.length - 1; j >= 0; j--) {
                    val = propObjs[j][name];

                    if (typeof val === 'object') {
                        complexObjs.unshift(val);
                    } else if (val !== undefined) {
                        dest[name] = val; // if there were no objects, this value will be used
                        break;
                    }
                }

                // if the trailing values were objects, use the merged value
                if (complexObjs.length) {
                    dest[name] = mergeProps(complexObjs);
                }
            }
        }

        // copy values into the destination, going from last to first
        for (i = propObjs.length - 1; i >= 0; i--) {
            props = propObjs[i];

            for (name in props) {
                if (!(name in dest)) { // if already assigned by previous props or complex props, don't reassign
                    dest[name] = props[name];
                }
            }
        }

        return dest;
    }


// Create an object that has the given prototype. Just like Object.create
    function createObject(proto) {
        var f = function () {};
        f.prototype = proto;
        return new f();
    }


    function copyOwnProps(src, dest) {
        for (var name in src) {
            if (hasOwnProp(src, name)) {
                dest[name] = src[name];
            }
        }
    }


// Copies over certain methods with the same names as Object.prototype methods. Overcomes an IE<=8 bug:
// https://developer.mozilla.org/en-US/docs/ECMAScript_DontEnum_attribute#JScript_DontEnum_Bug
    function copyNativeMethods(src, dest) {
        var names = ['constructor', 'toString', 'valueOf'];
        var i, name;

        for (i = 0; i < names.length; i++) {
            name = names[i];

            if (src[name] !== Object.prototype[name]) {
                dest[name] = src[name];
            }
        }
    }


    function hasOwnProp(obj, name) {
        return hasOwnPropMethod.call(obj, name);
    }


// Is the given value a non-object non-function value?
    function isAtomic(val) {
        return /undefined|null|boolean|number|string/.test($.type(val));
    }


    function applyAll(functions, thisObj, args) {
        if ($.isFunction(functions)) {
            functions = [functions];
        }
        if (functions) {
            var i;
            var ret;
            for (i = 0; i < functions.length; i++) {
                ret = functions[i].apply(thisObj, args) || ret;
            }
            return ret;
        }
    }


    function firstDefined() {
        for (var i = 0; i < arguments.length; i++) {
            if (arguments[i] !== undefined) {
                return arguments[i];
            }
        }
    }


    function htmlEscape(s) {
        return (s + '').replace(/&/g, '&amp;')
                .replace(/</g, '&lt;')
                .replace(/>/g, '&gt;')
                .replace(/'/g, '&#039;')
                .replace(/"/g, '&quot;')
                .replace(/\n/g, '<br />');
    }


    function stripHtmlEntities(text) {
        return text.replace(/&.*?;/g, '');
    }


// Given a hash of CSS properties, returns a string of CSS.
// Uses property names as-is (no camel-case conversion). Will not make statements for null/undefined values.
    function cssToStr(cssProps) {
        var statements = [];

        $.each(cssProps, function (name, val) {
            if (val != null) {
                statements.push(name + ':' + val);
            }
        });

        return statements.join(';');
    }


    function capitaliseFirstLetter(str) {
        return str.charAt(0).toUpperCase() + str.slice(1);
    }


    function compareNumbers(a, b) { // for .sort()
        return a - b;
    }


    function isInt(n) {
        return n % 1 === 0;
    }


// Returns a method bound to the given object context.
// Just like one of the jQuery.proxy signatures, but without the undesired behavior of treating the same method with
// different contexts as identical when binding/unbinding events.
    function proxy(obj, methodName) {
        var method = obj[methodName];

        return function () {
            return method.apply(obj, arguments);
        };
    }


// Returns a function, that, as long as it continues to be invoked, will not
// be triggered. The function will be called after it stops being called for
// N milliseconds. If `immediate` is passed, trigger the function on the
// leading edge, instead of the trailing.
// https://github.com/jashkenas/underscore/blob/1.6.0/underscore.js#L714
    function debounce(func, wait, immediate) {
        var timeout, args, context, timestamp, result;

        var later = function () {
            var last = +new Date() - timestamp;
            if (last < wait) {
                timeout = setTimeout(later, wait - last);
            } else {
                timeout = null;
                if (!immediate) {
                    result = func.apply(context, args);
                    context = args = null;
                }
            }
        };

        return function () {
            context = this;
            args = arguments;
            timestamp = +new Date();
            var callNow = immediate && !timeout;
            if (!timeout) {
                timeout = setTimeout(later, wait);
            }
            if (callNow) {
                result = func.apply(context, args);
                context = args = null;
            }
            return result;
        };
    }


// HACK around jQuery's now A+ promises: execute callback synchronously if already resolved.
// thenFunc shouldn't accept args.
// similar to whenResources in Scheduler plugin.
    function syncThen(promise, thenFunc) {
        // not a promise, or an already-resolved promise?
        if (!promise || !promise.then || promise.state() === 'resolved') {
            return $.when(thenFunc()); // resolve immediately
        } else if (thenFunc) {
            return promise.then(thenFunc);
        }
    }

    ;
    ;

    var ambigDateOfMonthRegex = /^\s*\d{4}-\d\d$/;
    var ambigTimeOrZoneRegex =
            /^\s*\d{4}-(?:(\d\d-\d\d)|(W\d\d$)|(W\d\d-\d)|(\d\d\d))((T| )(\d\d(:\d\d(:\d\d(\.\d+)?)?)?)?)?$/;
    var newMomentProto = moment.fn; // where we will attach our new methods
    var oldMomentProto = $.extend({}, newMomentProto); // copy of original moment methods
    var allowValueOptimization;
    var setUTCValues; // function defined below
    var setLocalValues; // function defined below


// Creating
// -------------------------------------------------------------------------------------------------

// Creates a new moment, similar to the vanilla moment(...) constructor, but with
// extra features (ambiguous time, enhanced formatting). When given an existing moment,
// it will function as a clone (and retain the zone of the moment). Anything else will
// result in a moment in the local zone.
    FC.moment = function () {
        return makeMoment(arguments);
    };

// Sames as FC.moment, but forces the resulting moment to be in the UTC timezone.
    FC.moment.utc = function () {
        var mom = makeMoment(arguments, true);

        // Force it into UTC because makeMoment doesn't guarantee it
        // (if given a pre-existing moment for example)
        if (mom.hasTime()) { // don't give ambiguously-timed moments a UTC zone
            mom.utc();
        }

        return mom;
    };

// Same as FC.moment, but when given an ISO8601 string, the timezone offset is preserved.
// ISO8601 strings with no timezone offset will become ambiguously zoned.
    FC.moment.parseZone = function () {
        return makeMoment(arguments, true, true);
    };

// Builds an enhanced moment from args. When given an existing moment, it clones. When given a
// native Date, or called with no arguments (the current time), the resulting moment will be local.
// Anything else needs to be "parsed" (a string or an array), and will be affected by:
//    parseAsUTC - if there is no zone information, should we parse the input in UTC?
//    parseZone - if there is zone information, should we force the zone of the moment?
    function makeMoment(args, parseAsUTC, parseZone) {
        var input = args[0];
        var isSingleString = args.length == 1 && typeof input === 'string';
        var isAmbigTime;
        var isAmbigZone;
        var ambigMatch;
        var mom;

        if (moment.isMoment(input)) {
            mom = moment.apply(null, args); // clone it
            transferAmbigs(input, mom); // the ambig flags weren't transfered with the clone
        } else if (isNativeDate(input) || input === undefined) {
            mom = moment.apply(null, args); // will be local
        } else { // "parsing" is required
            isAmbigTime = false;
            isAmbigZone = false;

            if (isSingleString) {
                if (ambigDateOfMonthRegex.test(input)) {
                    // accept strings like '2014-05', but convert to the first of the month
                    input += '-01';
                    args = [input]; // for when we pass it on to moment's constructor
                    isAmbigTime = true;
                    isAmbigZone = true;
                } else if ((ambigMatch = ambigTimeOrZoneRegex.exec(input))) {
                    isAmbigTime = !ambigMatch[5]; // no time part?
                    isAmbigZone = true;
                }
            } else if ($.isArray(input)) {
                // arrays have no timezone information, so assume ambiguous zone
                isAmbigZone = true;
            }
            // otherwise, probably a string with a format

            if (parseAsUTC || isAmbigTime) {
                mom = moment.utc.apply(moment, args);
            } else {
                mom = moment.apply(null, args);
            }

            if (isAmbigTime) {
                mom._ambigTime = true;
                mom._ambigZone = true; // ambiguous time always means ambiguous zone
            } else if (parseZone) { // let's record the inputted zone somehow
                if (isAmbigZone) {
                    mom._ambigZone = true;
                } else if (isSingleString) {
                    if (mom.utcOffset) {
                        mom.utcOffset(input); // if not a valid zone, will assign UTC
                    } else {
                        mom.zone(input); // for moment-pre-2.9
                    }
                }
            }
        }

        mom._fullCalendar = true; // flag for extended functionality

        return mom;
    }


// A clone method that works with the flags related to our enhanced functionality.
// In the future, use moment.momentProperties
    newMomentProto.clone = function () {
        var mom = oldMomentProto.clone.apply(this, arguments);

        // these flags weren't transfered with the clone
        transferAmbigs(this, mom);
        if (this._fullCalendar) {
            mom._fullCalendar = true;
        }

        return mom;
    };


// Week Number
// -------------------------------------------------------------------------------------------------


// Returns the week number, considering the locale's custom week number calcuation
// `weeks` is an alias for `week`
    newMomentProto.week = newMomentProto.weeks = function (input) {
        var weekCalc = (this._locale || this._lang) // works pre-moment-2.8
                ._fullCalendar_weekCalc;

        if (input == null && typeof weekCalc === 'function') { // custom function only works for getter
            return weekCalc(this);
        } else if (weekCalc === 'ISO') {
            return oldMomentProto.isoWeek.apply(this, arguments); // ISO getter/setter
        }

        return oldMomentProto.week.apply(this, arguments); // local getter/setter
    };


// Time-of-day
// -------------------------------------------------------------------------------------------------

// GETTER
// Returns a Duration with the hours/minutes/seconds/ms values of the moment.
// If the moment has an ambiguous time, a duration of 00:00 will be returned.
//
// SETTER
// You can supply a Duration, a Moment, or a Duration-like argument.
// When setting the time, and the moment has an ambiguous time, it then becomes unambiguous.
    newMomentProto.time = function (time) {

        // Fallback to the original method (if there is one) if this moment wasn't created via FullCalendar.
        // `time` is a generic enough method name where this precaution is necessary to avoid collisions w/ other plugins.
        if (!this._fullCalendar) {
            return oldMomentProto.time.apply(this, arguments);
        }

        if (time == null) { // getter
            return moment.duration({
                hours: this.hours(),
                minutes: this.minutes(),
                seconds: this.seconds(),
                milliseconds: this.milliseconds()
            });
        } else { // setter

            this._ambigTime = false; // mark that the moment now has a time

            if (!moment.isDuration(time) && !moment.isMoment(time)) {
                time = moment.duration(time);
            }

            // The day value should cause overflow (so 24 hours becomes 00:00:00 of next day).
            // Only for Duration times, not Moment times.
            var dayHours = 0;
            if (moment.isDuration(time)) {
                dayHours = Math.floor(time.asDays()) * 24;
            }

            // We need to set the individual fields.
            // Can't use startOf('day') then add duration. In case of DST at start of day.
            return this.hours(dayHours + time.hours())
                    .minutes(time.minutes())
                    .seconds(time.seconds())
                    .milliseconds(time.milliseconds());
        }
    };

// Converts the moment to UTC, stripping out its time-of-day and timezone offset,
// but preserving its YMD. A moment with a stripped time will display no time
// nor timezone offset when .format() is called.
    newMomentProto.stripTime = function () {
        var a;

        if (!this._ambigTime) {

            // get the values before any conversion happens
            a = this.toArray(); // array of y/m/d/h/m/s/ms

            // TODO: use keepLocalTime in the future
            this.utc(); // set the internal UTC flag (will clear the ambig flags)
            setUTCValues(this, a.slice(0, 3)); // set the year/month/date. time will be zero

            // Mark the time as ambiguous. This needs to happen after the .utc() call, which might call .utcOffset(),
            // which clears all ambig flags. Same with setUTCValues with moment-timezone.
            this._ambigTime = true;
            this._ambigZone = true; // if ambiguous time, also ambiguous timezone offset
        }

        return this; // for chaining
    };

// Returns if the moment has a non-ambiguous time (boolean)
    newMomentProto.hasTime = function () {
        return !this._ambigTime;
    };


// Timezone
// -------------------------------------------------------------------------------------------------

// Converts the moment to UTC, stripping out its timezone offset, but preserving its
// YMD and time-of-day. A moment with a stripped timezone offset will display no
// timezone offset when .format() is called.
// TODO: look into Moment's keepLocalTime functionality
    newMomentProto.stripZone = function () {
        var a, wasAmbigTime;

        if (!this._ambigZone) {

            // get the values before any conversion happens
            a = this.toArray(); // array of y/m/d/h/m/s/ms
            wasAmbigTime = this._ambigTime;

            this.utc(); // set the internal UTC flag (might clear the ambig flags, depending on Moment internals)
            setUTCValues(this, a); // will set the year/month/date/hours/minutes/seconds/ms

            // the above call to .utc()/.utcOffset() unfortunately might clear the ambig flags, so restore
            this._ambigTime = wasAmbigTime || false;

            // Mark the zone as ambiguous. This needs to happen after the .utc() call, which might call .utcOffset(),
            // which clears the ambig flags. Same with setUTCValues with moment-timezone.
            this._ambigZone = true;
        }

        return this; // for chaining
    };

// Returns of the moment has a non-ambiguous timezone offset (boolean)
    newMomentProto.hasZone = function () {
        return !this._ambigZone;
    };


// this method implicitly marks a zone
    newMomentProto.local = function () {
        var a = this.toArray(); // year,month,date,hours,minutes,seconds,ms as an array
        var wasAmbigZone = this._ambigZone;

        oldMomentProto.local.apply(this, arguments);

        // ensure non-ambiguous
        // this probably already happened via local() -> utcOffset(), but don't rely on Moment's internals
        this._ambigTime = false;
        this._ambigZone = false;

        if (wasAmbigZone) {
            // If the moment was ambiguously zoned, the date fields were stored as UTC.
            // We want to preserve these, but in local time.
            // TODO: look into Moment's keepLocalTime functionality
            setLocalValues(this, a);
        }

        return this; // for chaining
    };


// implicitly marks a zone
    newMomentProto.utc = function () {
        oldMomentProto.utc.apply(this, arguments);

        // ensure non-ambiguous
        // this probably already happened via utc() -> utcOffset(), but don't rely on Moment's internals
        this._ambigTime = false;
        this._ambigZone = false;

        return this;
    };


// methods for arbitrarily manipulating timezone offset.
// should clear time/zone ambiguity when called.
    $.each([
        'zone', // only in moment-pre-2.9. deprecated afterwards
        'utcOffset'
    ], function (i, name) {
        if (oldMomentProto[name]) { // original method exists?

            // this method implicitly marks a zone (will probably get called upon .utc() and .local())
            newMomentProto[name] = function (tzo) {

                if (tzo != null) { // setter
                    // these assignments needs to happen before the original zone method is called.
                    // I forget why, something to do with a browser crash.
                    this._ambigTime = false;
                    this._ambigZone = false;
                }

                return oldMomentProto[name].apply(this, arguments);
            };
        }
    });


// Formatting
// -------------------------------------------------------------------------------------------------

    newMomentProto.format = function () {
        if (this._fullCalendar && arguments[0]) { // an enhanced moment? and a format string provided?
            return formatDate(this, arguments[0]); // our extended formatting
        }
        if (this._ambigTime) {
            return oldMomentFormat(this, 'YYYY-MM-DD');
        }
        if (this._ambigZone) {
            return oldMomentFormat(this, 'YYYY-MM-DD[T]HH:mm:ss');
        }
        return oldMomentProto.format.apply(this, arguments);
    };

    newMomentProto.toISOString = function () {
        if (this._ambigTime) {
            return oldMomentFormat(this, 'YYYY-MM-DD');
        }
        if (this._ambigZone) {
            return oldMomentFormat(this, 'YYYY-MM-DD[T]HH:mm:ss');
        }
        return oldMomentProto.toISOString.apply(this, arguments);
    };


// Querying
// -------------------------------------------------------------------------------------------------

// Is the moment within the specified range? `end` is exclusive.
// FYI, this method is not a standard Moment method, so always do our enhanced logic.
    newMomentProto.isWithin = function (start, end) {
        var a = commonlyAmbiguate([this, start, end]);
        return a[0] >= a[1] && a[0] < a[2];
    };

// When isSame is called with units, timezone ambiguity is normalized before the comparison happens.
// If no units specified, the two moments must be identically the same, with matching ambig flags.
    newMomentProto.isSame = function (input, units) {
        var a;

        // only do custom logic if this is an enhanced moment
        if (!this._fullCalendar) {
            return oldMomentProto.isSame.apply(this, arguments);
        }

        if (units) {
            a = commonlyAmbiguate([this, input], true); // normalize timezones but don't erase times
            return oldMomentProto.isSame.call(a[0], a[1], units);
        } else {
            input = FC.moment.parseZone(input); // normalize input
            return oldMomentProto.isSame.call(this, input) &&
                    Boolean(this._ambigTime) === Boolean(input._ambigTime) &&
                    Boolean(this._ambigZone) === Boolean(input._ambigZone);
        }
    };

// Make these query methods work with ambiguous moments
    $.each([
        'isBefore',
        'isAfter'
    ], function (i, methodName) {
        newMomentProto[methodName] = function (input, units) {
            var a;

            // only do custom logic if this is an enhanced moment
            if (!this._fullCalendar) {
                return oldMomentProto[methodName].apply(this, arguments);
            }

            a = commonlyAmbiguate([this, input]);
            return oldMomentProto[methodName].call(a[0], a[1], units);
        };
    });


// Misc Internals
// -------------------------------------------------------------------------------------------------

// given an array of moment-like inputs, return a parallel array w/ moments similarly ambiguated.
// for example, of one moment has ambig time, but not others, all moments will have their time stripped.
// set `preserveTime` to `true` to keep times, but only normalize zone ambiguity.
// returns the original moments if no modifications are necessary.
    function commonlyAmbiguate(inputs, preserveTime) {
        var anyAmbigTime = false;
        var anyAmbigZone = false;
        var len = inputs.length;
        var moms = [];
        var i, mom;

        // parse inputs into real moments and query their ambig flags
        for (i = 0; i < len; i++) {
            mom = inputs[i];
            if (!moment.isMoment(mom)) {
                mom = FC.moment.parseZone(mom);
            }
            anyAmbigTime = anyAmbigTime || mom._ambigTime;
            anyAmbigZone = anyAmbigZone || mom._ambigZone;
            moms.push(mom);
        }

        // strip each moment down to lowest common ambiguity
        // use clones to avoid modifying the original moments
        for (i = 0; i < len; i++) {
            mom = moms[i];
            if (!preserveTime && anyAmbigTime && !mom._ambigTime) {
                moms[i] = mom.clone().stripTime();
            } else if (anyAmbigZone && !mom._ambigZone) {
                moms[i] = mom.clone().stripZone();
            }
        }

        return moms;
    }

// Transfers all the flags related to ambiguous time/zone from the `src` moment to the `dest` moment
// TODO: look into moment.momentProperties for this.
    function transferAmbigs(src, dest) {
        if (src._ambigTime) {
            dest._ambigTime = true;
        } else if (dest._ambigTime) {
            dest._ambigTime = false;
        }

        if (src._ambigZone) {
            dest._ambigZone = true;
        } else if (dest._ambigZone) {
            dest._ambigZone = false;
        }
    }


// Sets the year/month/date/etc values of the moment from the given array.
// Inefficient because it calls each individual setter.
    function setMomentValues(mom, a) {
        mom.year(a[0] || 0)
                .month(a[1] || 0)
                .date(a[2] || 0)
                .hours(a[3] || 0)
                .minutes(a[4] || 0)
                .seconds(a[5] || 0)
                .milliseconds(a[6] || 0);
    }

// Can we set the moment's internal date directly?
    allowValueOptimization = '_d' in moment() && 'updateOffset' in moment;

// Utility function. Accepts a moment and an array of the UTC year/month/date/etc values to set.
// Assumes the given moment is already in UTC mode.
    setUTCValues = allowValueOptimization ? function (mom, a) {
        // simlate what moment's accessors do
        mom._d.setTime(Date.UTC.apply(Date, a));
        moment.updateOffset(mom, false); // keepTime=false
    } : setMomentValues;

// Utility function. Accepts a moment and an array of the local year/month/date/etc values to set.
// Assumes the given moment is already in local mode.
    setLocalValues = allowValueOptimization ? function (mom, a) {
        // simlate what moment's accessors do
        mom._d.setTime(+new Date(// FYI, there is now way to apply an array of args to a constructor
                a[0] || 0,
                a[1] || 0,
                a[2] || 0,
                a[3] || 0,
                a[4] || 0,
                a[5] || 0,
                a[6] || 0
                ));
        moment.updateOffset(mom, false); // keepTime=false
    } : setMomentValues;

    ;
    ;

// Single Date Formatting
// -------------------------------------------------------------------------------------------------


// call this if you want Moment's original format method to be used
    function oldMomentFormat(mom, formatStr) {
        return oldMomentProto.format.call(mom, formatStr); // oldMomentProto defined in moment-ext.js
    }


// Formats `date` with a Moment formatting string, but allow our non-zero areas and
// additional token.
    function formatDate(date, formatStr) {
        return formatDateWithChunks(date, getFormatStringChunks(formatStr));
    }


    function formatDateWithChunks(date, chunks) {
        var s = '';
        var i;

        for (i = 0; i < chunks.length; i++) {
            s += formatDateWithChunk(date, chunks[i]);
        }

        return s;
    }


// addition formatting tokens we want recognized
    var tokenOverrides = {
        t: function (date) { // "a" or "p"
            return oldMomentFormat(date, 'a').charAt(0);
        },
        T: function (date) { // "A" or "P"
            return oldMomentFormat(date, 'A').charAt(0);
        }
    };


    function formatDateWithChunk(date, chunk) {
        var token;
        var maybeStr;

        if (typeof chunk === 'string') { // a literal string
            return chunk;
        } else if ((token = chunk.token)) { // a token, like "YYYY"
            if (tokenOverrides[token]) {
                return tokenOverrides[token](date); // use our custom token
            }
            return oldMomentFormat(date, token);
        } else if (chunk.maybe) { // a grouping of other chunks that must be non-zero
            maybeStr = formatDateWithChunks(date, chunk.maybe);
            if (maybeStr.match(/[1-9]/)) {
                return maybeStr;
            }
        }

        return '';
    }


// Date Range Formatting
// -------------------------------------------------------------------------------------------------
// TODO: make it work with timezone offset

// Using a formatting string meant for a single date, generate a range string, like
// "Sep 2 - 9 2013", that intelligently inserts a separator where the dates differ.
// If the dates are the same as far as the format string is concerned, just return a single
// rendering of one date, without any separator.
    function formatRange(date1, date2, formatStr, separator, isRTL) {
        var localeData;

        date1 = FC.moment.parseZone(date1);
        date2 = FC.moment.parseZone(date2);

        localeData = (date1.localeData || date1.lang).call(date1); // works with moment-pre-2.8

        // Expand localized format strings, like "LL" -> "MMMM D YYYY"
        formatStr = localeData.longDateFormat(formatStr) || formatStr;
        // BTW, this is not important for `formatDate` because it is impossible to put custom tokens
        // or non-zero areas in Moment's localized format strings.

        separator = separator || ' - ';

        return formatRangeWithChunks(
                date1,
                date2,
                getFormatStringChunks(formatStr),
                separator,
                isRTL
                );
    }
    FC.formatRange = formatRange; // expose


    function formatRangeWithChunks(date1, date2, chunks, separator, isRTL) {
        var unzonedDate1 = date1.clone().stripZone(); // for formatSimilarChunk
        var unzonedDate2 = date2.clone().stripZone(); // "
        var chunkStr; // the rendering of the chunk
        var leftI;
        var leftStr = '';
        var rightI;
        var rightStr = '';
        var middleI;
        var middleStr1 = '';
        var middleStr2 = '';
        var middleStr = '';

        // Start at the leftmost side of the formatting string and continue until you hit a token
        // that is not the same between dates.
        for (leftI = 0; leftI < chunks.length; leftI++) {
            chunkStr = formatSimilarChunk(date1, date2, unzonedDate1, unzonedDate2, chunks[leftI]);
            if (chunkStr === false) {
                break;
            }
            leftStr += chunkStr;
        }

        // Similarly, start at the rightmost side of the formatting string and move left
        for (rightI = chunks.length - 1; rightI > leftI; rightI--) {
            chunkStr = formatSimilarChunk(date1, date2, unzonedDate1, unzonedDate2, chunks[rightI]);
            if (chunkStr === false) {
                break;
            }
            rightStr = chunkStr + rightStr;
        }

        // The area in the middle is different for both of the dates.
        // Collect them distinctly so we can jam them together later.
        for (middleI = leftI; middleI <= rightI; middleI++) {
            middleStr1 += formatDateWithChunk(date1, chunks[middleI]);
            middleStr2 += formatDateWithChunk(date2, chunks[middleI]);
        }

        if (middleStr1 || middleStr2) {
            if (isRTL) {
                middleStr = middleStr2 + separator + middleStr1;
            } else {
                middleStr = middleStr1 + separator + middleStr2;
            }
        }

        return leftStr + middleStr + rightStr;
    }


    var similarUnitMap = {
        Y: 'year',
        M: 'month',
        D: 'day', // day of month
        d: 'day', // day of week
        // prevents a separator between anything time-related...
        A: 'second', // AM/PM
        a: 'second', // am/pm
        T: 'second', // A/P
        t: 'second', // a/p
        H: 'second', // hour (24)
        h: 'second', // hour (12)
        m: 'second', // minute
        s: 'second' // second
    };
// TODO: week maybe?


// Given a formatting chunk, and given that both dates are similar in the regard the
// formatting chunk is concerned, format date1 against `chunk`. Otherwise, return `false`.
    function formatSimilarChunk(date1, date2, unzonedDate1, unzonedDate2, chunk) {
        var token;
        var unit;

        if (typeof chunk === 'string') { // a literal string
            return chunk;
        } else if ((token = chunk.token)) {
            unit = similarUnitMap[token.charAt(0)];

            // are the dates the same for this unit of measurement?
            // use the unzoned dates for this calculation because unreliable when near DST (bug #2396)
            if (unit && unzonedDate1.isSame(unzonedDate2, unit)) {
                return oldMomentFormat(date1, token); // would be the same if we used `date2`
                // BTW, don't support custom tokens
            }
        }

        return false; // the chunk is NOT the same for the two dates
        // BTW, don't support splitting on non-zero areas
    }


// Chunking Utils
// -------------------------------------------------------------------------------------------------


    var formatStringChunkCache = {};


    function getFormatStringChunks(formatStr) {
        if (formatStr in formatStringChunkCache) {
            return formatStringChunkCache[formatStr];
        }
        return (formatStringChunkCache[formatStr] = chunkFormatString(formatStr));
    }


// Break the formatting string into an array of chunks
    function chunkFormatString(formatStr) {
        var chunks = [];
        var chunker = /\[([^\]]*)\]|\(([^\)]*)\)|(LTS|LT|(\w)\4*o?)|([^\w\[\(]+)/g; // TODO: more descrimination
        var match;

        while ((match = chunker.exec(formatStr))) {
            if (match[1]) { // a literal string inside [ ... ]
                chunks.push(match[1]);
            } else if (match[2]) { // non-zero formatting inside ( ... )
                chunks.push({maybe: chunkFormatString(match[2])});
            } else if (match[3]) { // a formatting token
                chunks.push({token: match[3]});
            } else if (match[5]) { // an unenclosed literal string
                chunks.push(match[5]);
            }
        }

        return chunks;
    }

    ;
    ;

    FC.Class = Class; // export

// Class that all other classes will inherit from
    function Class() { }


// Called on a class to create a subclass.
// Last argument contains instance methods. Any argument before the last are considered mixins.
    Class.extend = function () {
        var len = arguments.length;
        var i;
        var members;

        for (i = 0; i < len; i++) {
            members = arguments[i];
            if (i < len - 1) { // not the last argument?
                mixIntoClass(this, members);
            }
        }

        return extendClass(this, members || {}); // members will be undefined if no arguments
    };


// Adds new member variables/methods to the class's prototype.
// Can be called with another class, or a plain object hash containing new members.
    Class.mixin = function (members) {
        mixIntoClass(this, members);
    };


    function extendClass(superClass, members) {
        var subClass;

        // ensure a constructor for the subclass, forwarding all arguments to the super-constructor if it doesn't exist
        if (hasOwnProp(members, 'constructor')) {
            subClass = members.constructor;
        }
        if (typeof subClass !== 'function') {
            subClass = members.constructor = function () {
                superClass.apply(this, arguments);
            };
        }

        // build the base prototype for the subclass, which is an new object chained to the superclass's prototype
        subClass.prototype = createObject(superClass.prototype);

        // copy each member variable/method onto the the subclass's prototype
        copyOwnProps(members, subClass.prototype);
        copyNativeMethods(members, subClass.prototype); // hack for IE8

        // copy over all class variables/methods to the subclass, such as `extend` and `mixin`
        copyOwnProps(superClass, subClass);

        return subClass;
    }


    function mixIntoClass(theClass, members) {
        copyOwnProps(members, theClass.prototype); // TODO: copyNativeMethods?
    }
    ;
    ;

    var EmitterMixin = FC.EmitterMixin = {
        // jQuery-ification via $(this) allows a non-DOM object to have
        // the same event handling capabilities (including namespaces).


        on: function (types, handler) {

            // handlers are always called with an "event" object as their first param.
            // sneak the `this` context and arguments into the extra parameter object
            // and forward them on to the original handler.
            var intercept = function (ev, extra) {
                return handler.apply(
                        extra.context || this,
                        extra.args || []
                        );
            };

            // mimick jQuery's internal "proxy" system (risky, I know)
            // causing all functions with the same .guid to appear to be the same.
            // https://github.com/jquery/jquery/blob/2.2.4/src/core.js#L448
            // this is needed for calling .off with the original non-intercept handler.
            if (!handler.guid) {
                handler.guid = $.guid++;
            }
            intercept.guid = handler.guid;

            $(this).on(types, intercept);

            return this; // for chaining
        },
        off: function (types, handler) {
            $(this).off(types, handler);

            return this; // for chaining
        },
        trigger: function (types) {
            var args = Array.prototype.slice.call(arguments, 1); // arguments after the first

            // pass in "extra" info to the intercept
            $(this).triggerHandler(types, {args: args});

            return this; // for chaining
        },
        triggerWith: function (types, context, args) {

            // `triggerHandler` is less reliant on the DOM compared to `trigger`.
            // pass in "extra" info to the intercept.
            $(this).triggerHandler(types, {context: context, args: args});

            return this; // for chaining
        }

    };

    ;
    ;

    /*
     Utility methods for easily listening to events on another object,
     and more importantly, easily unlistening from them.
     */
    var ListenerMixin = FC.ListenerMixin = (function () {
        var guid = 0;
        var ListenerMixin = {
            listenerId: null,
            /*
             Given an `other` object that has on/off methods, bind the given `callback` to an event by the given name.
             The `callback` will be called with the `this` context of the object that .listenTo is being called on.
             Can be called:
             .listenTo(other, eventName, callback)
             OR
             .listenTo(other, {
             eventName1: callback1,
             eventName2: callback2
             })
             */
            listenTo: function (other, arg, callback) {
                if (typeof arg === 'object') { // given dictionary of callbacks
                    for (var eventName in arg) {
                        if (arg.hasOwnProperty(eventName)) {
                            this.listenTo(other, eventName, arg[eventName]);
                        }
                    }
                } else if (typeof arg === 'string') {
                    other.on(
                            arg + '.' + this.getListenerNamespace(), // use event namespacing to identify this object
                            $.proxy(callback, this) // always use `this` context
                            // the usually-undesired jQuery guid behavior doesn't matter,
                            // because we always unbind via namespace
                            );
                }
            },
            /*
             Causes the current object to stop listening to events on the `other` object.
             `eventName` is optional. If omitted, will stop listening to ALL events on `other`.
             */
            stopListeningTo: function (other, eventName) {
                other.off((eventName || '') + '.' + this.getListenerNamespace());
            },
            /*
             Returns a string, unique to this object, to be used for event namespacing
             */
            getListenerNamespace: function () {
                if (this.listenerId == null) {
                    this.listenerId = guid++;
                }
                return '_listener' + this.listenerId;
            }

        };
        return ListenerMixin;
    })();
    ;
    ;

// simple class for toggle a `isIgnoringMouse` flag on delay
// initMouseIgnoring must first be called, with a millisecond delay setting.
    var MouseIgnorerMixin = {
        isIgnoringMouse: false, // bool
        delayUnignoreMouse: null, // method


        initMouseIgnoring: function (delay) {
            this.delayUnignoreMouse = debounce(proxy(this, 'unignoreMouse'), delay || 1000);
        },
        // temporarily ignore mouse actions on segments
        tempIgnoreMouse: function () {
            this.isIgnoringMouse = true;
            this.delayUnignoreMouse();
        },
        // delayUnignoreMouse eventually calls this
        unignoreMouse: function () {
            this.isIgnoringMouse = false;
        }

    };

    ;
    ;

    /* A rectangular panel that is absolutely positioned over other content
     ------------------------------------------------------------------------------------------------------------------------
     Options:
     - className (string)
     - content (HTML string or jQuery element set)
     - parentEl
     - top
     - left
     - right (the x coord of where the right edge should be. not a "CSS" right)
     - autoHide (boolean)
     - show (callback)
     - hide (callback)
     */

    var Popover = Class.extend(ListenerMixin, {
        isHidden: true,
        options: null,
        el: null, // the container element for the popover. generated by this object
        margin: 10, // the space required between the popover and the edges of the scroll container


        constructor: function (options) {
            this.options = options || {};
        },
        // Shows the popover on the specified position. Renders it if not already
        show: function () {
            if (this.isHidden) {
                if (!this.el) {
                    this.render();
                }
                this.el.show();
                this.position();
                this.isHidden = false;
                this.trigger('show');
            }
        },
        // Hides the popover, through CSS, but does not remove it from the DOM
        hide: function () {
            if (!this.isHidden) {
                this.el.hide();
                this.isHidden = true;
                this.trigger('hide');
            }
        },
        // Creates `this.el` and renders content inside of it
        render: function () {
            var _this = this;
            var options = this.options;

            this.el = $('<div class="fc-popover"/>')
                    .addClass(options.className || '')
                    .css({
                        // position initially to the top left to avoid creating scrollbars
                        top: 0,
                        left: 0
                    })
                    .append(options.content)
                    .appendTo(options.parentEl);

            // when a click happens on anything inside with a 'fc-close' className, hide the popover
            this.el.on('click', '.fc-close', function () {
                _this.hide();
            });

            if (options.autoHide) {
                this.listenTo($(document), 'mousedown', this.documentMousedown);
            }
        },
        // Triggered when the user clicks *anywhere* in the document, for the autoHide feature
        documentMousedown: function (ev) {
            // only hide the popover if the click happened outside the popover
            if (this.el && !$(ev.target).closest(this.el).length) {
                this.hide();
            }
        },
        // Hides and unregisters any handlers
        removeElement: function () {
            this.hide();

            if (this.el) {
                this.el.remove();
                this.el = null;
            }

            this.stopListeningTo($(document), 'mousedown');
        },
        // Positions the popover optimally, using the top/left/right options
        position: function () {
            var options = this.options;
            var origin = this.el.offsetParent().offset();
            var width = this.el.outerWidth();
            var height = this.el.outerHeight();
            var windowEl = $(window);
            var viewportEl = getScrollParent(this.el);
            var viewportTop;
            var viewportLeft;
            var viewportOffset;
            var top; // the "position" (not "offset") values for the popover
            var left; //

            // compute top and left
            top = options.top || 0;
            if (options.left !== undefined) {
                left = options.left;
            } else if (options.right !== undefined) {
                left = options.right - width; // derive the left value from the right value
            } else {
                left = 0;
            }

            if (viewportEl.is(window) || viewportEl.is(document)) { // normalize getScrollParent's result
                viewportEl = windowEl;
                viewportTop = 0; // the window is always at the top left
                viewportLeft = 0; // (and .offset() won't work if called here)
            } else {
                viewportOffset = viewportEl.offset();
                viewportTop = viewportOffset.top;
                viewportLeft = viewportOffset.left;
            }

            // if the window is scrolled, it causes the visible area to be further down
            viewportTop += windowEl.scrollTop();
            viewportLeft += windowEl.scrollLeft();

            // constrain to the view port. if constrained by two edges, give precedence to top/left
            if (options.viewportConstrain !== false) {
                top = Math.min(top, viewportTop + viewportEl.outerHeight() - height - this.margin);
                top = Math.max(top, viewportTop + this.margin);
                left = Math.min(left, viewportLeft + viewportEl.outerWidth() - width - this.margin);
                left = Math.max(left, viewportLeft + this.margin);
            }

            this.el.css({
                top: top - origin.top,
                left: left - origin.left
            });
        },
        // Triggers a callback. Calls a function in the option hash of the same name.
        // Arguments beyond the first `name` are forwarded on.
        // TODO: better code reuse for this. Repeat code
        trigger: function (name) {
            if (this.options[name]) {
                this.options[name].apply(this, Array.prototype.slice.call(arguments, 1));
            }
        }

    });

    ;
    ;

    /*
     A cache for the left/right/top/bottom/width/height values for one or more elements.
     Works with both offset (from topleft document) and position (from offsetParent).
     
     options:
     - els
     - isHorizontal
     - isVertical
     */
    var CoordCache = FC.CoordCache = Class.extend({
        els: null, // jQuery set (assumed to be siblings)
        forcedOffsetParentEl: null, // options can override the natural offsetParent
        origin: null, // {left,top} position of offsetParent of els
        boundingRect: null, // constrain cordinates to this rectangle. {left,right,top,bottom} or null
        isHorizontal: false, // whether to query for left/right/width
        isVertical: false, // whether to query for top/bottom/height

        // arrays of coordinates (offsets from topleft of document)
        lefts: null,
        rights: null,
        tops: null,
        bottoms: null,
        constructor: function (options) {
            this.els = $(options.els);
            this.isHorizontal = options.isHorizontal;
            this.isVertical = options.isVertical;
            this.forcedOffsetParentEl = options.offsetParent ? $(options.offsetParent) : null;
        },
        // Queries the els for coordinates and stores them.
        // Call this method before using and of the get* methods below.
        build: function () {
            var offsetParentEl = this.forcedOffsetParentEl || this.els.eq(0).offsetParent();

            this.origin = offsetParentEl.offset();
            this.boundingRect = this.queryBoundingRect();

            if (this.isHorizontal) {
                this.buildElHorizontals();
            }
            if (this.isVertical) {
                this.buildElVerticals();
            }
        },
        // Destroys all internal data about coordinates, freeing memory
        clear: function () {
            this.origin = null;
            this.boundingRect = null;
            this.lefts = null;
            this.rights = null;
            this.tops = null;
            this.bottoms = null;
        },
        // When called, if coord caches aren't built, builds them
        ensureBuilt: function () {
            if (!this.origin) {
                this.build();
            }
        },
        // Compute and return what the elements' bounding rectangle is, from the user's perspective.
        // Right now, only returns a rectangle if constrained by an overflow:scroll element.
        queryBoundingRect: function () {
            var scrollParentEl = getScrollParent(this.els.eq(0));

            if (!scrollParentEl.is(document)) {
                return getClientRect(scrollParentEl);
            }
        },
        // Populates the left/right internal coordinate arrays
        buildElHorizontals: function () {
            var lefts = [];
            var rights = [];

            this.els.each(function (i, node) {
                var el = $(node);
                var left = el.offset().left;
                var width = el.outerWidth();

                lefts.push(left);
                rights.push(left + width);
            });

            this.lefts = lefts;
            this.rights = rights;
        },
        // Populates the top/bottom internal coordinate arrays
        buildElVerticals: function () {
            var tops = [];
            var bottoms = [];

            this.els.each(function (i, node) {
                var el = $(node);
                var top = el.offset().top;
                var height = el.outerHeight();

                tops.push(top);
                bottoms.push(top + height);
            });

            this.tops = tops;
            this.bottoms = bottoms;
        },
        // Given a left offset (from document left), returns the index of the el that it horizontally intersects.
        // If no intersection is made, or outside of the boundingRect, returns undefined.
        getHorizontalIndex: function (leftOffset) {
            this.ensureBuilt();

            var boundingRect = this.boundingRect;
            var lefts = this.lefts;
            var rights = this.rights;
            var len = lefts.length;
            var i;

            if (!boundingRect || (leftOffset >= boundingRect.left && leftOffset < boundingRect.right)) {
                for (i = 0; i < len; i++) {
                    if (leftOffset >= lefts[i] && leftOffset < rights[i]) {
                        return i;
                    }
                }
            }
        },
        // Given a top offset (from document top), returns the index of the el that it vertically intersects.
        // If no intersection is made, or outside of the boundingRect, returns undefined.
        getVerticalIndex: function (topOffset) {
            this.ensureBuilt();

            var boundingRect = this.boundingRect;
            var tops = this.tops;
            var bottoms = this.bottoms;
            var len = tops.length;
            var i;

            if (!boundingRect || (topOffset >= boundingRect.top && topOffset < boundingRect.bottom)) {
                for (i = 0; i < len; i++) {
                    if (topOffset >= tops[i] && topOffset < bottoms[i]) {
                        return i;
                    }
                }
            }
        },
        // Gets the left offset (from document left) of the element at the given index
        getLeftOffset: function (leftIndex) {
            this.ensureBuilt();
            return this.lefts[leftIndex];
        },
        // Gets the left position (from offsetParent left) of the element at the given index
        getLeftPosition: function (leftIndex) {
            this.ensureBuilt();
            return this.lefts[leftIndex] - this.origin.left;
        },
        // Gets the right offset (from document left) of the element at the given index.
        // This value is NOT relative to the document's right edge, like the CSS concept of "right" would be.
        getRightOffset: function (leftIndex) {
            this.ensureBuilt();
            return this.rights[leftIndex];
        },
        // Gets the right position (from offsetParent left) of the element at the given index.
        // This value is NOT relative to the offsetParent's right edge, like the CSS concept of "right" would be.
        getRightPosition: function (leftIndex) {
            this.ensureBuilt();
            return this.rights[leftIndex] - this.origin.left;
        },
        // Gets the width of the element at the given index
        getWidth: function (leftIndex) {
            this.ensureBuilt();
            return this.rights[leftIndex] - this.lefts[leftIndex];
        },
        // Gets the top offset (from document top) of the element at the given index
        getTopOffset: function (topIndex) {
            this.ensureBuilt();
            return this.tops[topIndex];
        },
        // Gets the top position (from offsetParent top) of the element at the given position
        getTopPosition: function (topIndex) {
            this.ensureBuilt();
            return this.tops[topIndex] - this.origin.top;
        },
        // Gets the bottom offset (from the document top) of the element at the given index.
        // This value is NOT relative to the offsetParent's bottom edge, like the CSS concept of "bottom" would be.
        getBottomOffset: function (topIndex) {
            this.ensureBuilt();
            return this.bottoms[topIndex];
        },
        // Gets the bottom position (from the offsetParent top) of the element at the given index.
        // This value is NOT relative to the offsetParent's bottom edge, like the CSS concept of "bottom" would be.
        getBottomPosition: function (topIndex) {
            this.ensureBuilt();
            return this.bottoms[topIndex] - this.origin.top;
        },
        // Gets the height of the element at the given index
        getHeight: function (topIndex) {
            this.ensureBuilt();
            return this.bottoms[topIndex] - this.tops[topIndex];
        }

    });

    ;
    ;

    /* Tracks a drag's mouse movement, firing various handlers
     ----------------------------------------------------------------------------------------------------------------------*/
// TODO: use Emitter

    var DragListener = FC.DragListener = Class.extend(ListenerMixin, MouseIgnorerMixin, {
        options: null,
        // for IE8 bug-fighting behavior
        subjectEl: null,
        subjectHref: null,
        // coordinates of the initial mousedown
        originX: null,
        originY: null,
        // the wrapping element that scrolls, or MIGHT scroll if there's overflow.
        // TODO: do this for wrappers that have overflow:hidden as well.
        scrollEl: null,
        isInteracting: false,
        isDistanceSurpassed: false,
        isDelayEnded: false,
        isDragging: false,
        isTouch: false,
        delay: null,
        delayTimeoutId: null,
        minDistance: null,
        handleTouchScrollProxy: null, // calls handleTouchScroll, always bound to `this`


        constructor: function (options) {
            this.options = options || {};
            this.handleTouchScrollProxy = proxy(this, 'handleTouchScroll');
            this.initMouseIgnoring(500);
        },
        // Interaction (high-level)
        // -----------------------------------------------------------------------------------------------------------------


        startInteraction: function (ev, extraOptions) {
            var isTouch = getEvIsTouch(ev);

            if (ev.type === 'mousedown') {
                if (this.isIgnoringMouse) {
                    return;
                } else if (!isPrimaryMouseButton(ev)) {
                    return;
                } else {
                    ev.preventDefault(); // prevents native selection in most browsers
                }
            }

            if (!this.isInteracting) {

                // process options
                extraOptions = extraOptions || {};
                this.delay = firstDefined(extraOptions.delay, this.options.delay, 0);
                this.minDistance = firstDefined(extraOptions.distance, this.options.distance, 0);
                this.subjectEl = this.options.subjectEl;

                this.isInteracting = true;
                this.isTouch = isTouch;
                this.isDelayEnded = false;
                this.isDistanceSurpassed = false;

                this.originX = getEvX(ev);
                this.originY = getEvY(ev);
                this.scrollEl = getScrollParent($(ev.target));

                this.bindHandlers();
                this.initAutoScroll();
                this.handleInteractionStart(ev);
                this.startDelay(ev);

                if (!this.minDistance) {
                    this.handleDistanceSurpassed(ev);
                }
            }
        },
        handleInteractionStart: function (ev) {
            this.trigger('interactionStart', ev);
        },
        endInteraction: function (ev, isCancelled) {
            if (this.isInteracting) {
                this.endDrag(ev);

                if (this.delayTimeoutId) {
                    clearTimeout(this.delayTimeoutId);
                    this.delayTimeoutId = null;
                }

                this.destroyAutoScroll();
                this.unbindHandlers();

                this.isInteracting = false;
                this.handleInteractionEnd(ev, isCancelled);

                // a touchstart+touchend on the same element will result in the following addition simulated events:
                // mouseover + mouseout + click
                // let's ignore these bogus events
                if (this.isTouch) {
                    this.tempIgnoreMouse();
                }
            }
        },
        handleInteractionEnd: function (ev, isCancelled) {
            this.trigger('interactionEnd', ev, isCancelled || false);
        },
        // Binding To DOM
        // -----------------------------------------------------------------------------------------------------------------


        bindHandlers: function () {
            var _this = this;
            var touchStartIgnores = 1;

            if (this.isTouch) {
                this.listenTo($(document), {
                    touchmove: this.handleTouchMove,
                    touchend: this.endInteraction,
                    touchcancel: this.endInteraction,
                    // Sometimes touchend doesn't fire
                    // (can't figure out why. touchcancel doesn't fire either. has to do with scrolling?)
                    // If another touchstart happens, we know it's bogus, so cancel the drag.
                    // touchend will continue to be broken until user does a shorttap/scroll, but this is best we can do.
                    touchstart: function (ev) {
                        if (touchStartIgnores) { // bindHandlers is called from within a touchstart,
                            touchStartIgnores--; // and we don't want this to fire immediately, so ignore.
                        } else {
                            _this.endInteraction(ev, true); // isCancelled=true
                        }
                    }
                });

                // listen to ALL scroll actions on the page
                if (
                        !bindAnyScroll(this.handleTouchScrollProxy) && // hopefully this works and short-circuits the rest
                        this.scrollEl // otherwise, attach a single handler to this
                        ) {
                    this.listenTo(this.scrollEl, 'scroll', this.handleTouchScroll);
                }
            } else {
                this.listenTo($(document), {
                    mousemove: this.handleMouseMove,
                    mouseup: this.endInteraction
                });
            }

            this.listenTo($(document), {
                selectstart: preventDefault, // don't allow selection while dragging
                contextmenu: preventDefault // long taps would open menu on Chrome dev tools
            });
        },
        unbindHandlers: function () {
            this.stopListeningTo($(document));

            // unbind scroll listening
            unbindAnyScroll(this.handleTouchScrollProxy);
            if (this.scrollEl) {
                this.stopListeningTo(this.scrollEl, 'scroll');
            }
        },
        // Drag (high-level)
        // -----------------------------------------------------------------------------------------------------------------


        // extraOptions ignored if drag already started
        startDrag: function (ev, extraOptions) {
            this.startInteraction(ev, extraOptions); // ensure interaction began

            if (!this.isDragging) {
                this.isDragging = true;
                this.handleDragStart(ev);
            }
        },
        handleDragStart: function (ev) {
            this.trigger('dragStart', ev);
            this.initHrefHack();
        },
        handleMove: function (ev) {
            var dx = getEvX(ev) - this.originX;
            var dy = getEvY(ev) - this.originY;
            var minDistance = this.minDistance;
            var distanceSq; // current distance from the origin, squared

            if (!this.isDistanceSurpassed) {
                distanceSq = dx * dx + dy * dy;
                if (distanceSq >= minDistance * minDistance) { // use pythagorean theorem
                    this.handleDistanceSurpassed(ev);
                }
            }

            if (this.isDragging) {
                this.handleDrag(dx, dy, ev);
            }
        },
        // Called while the mouse is being moved and when we know a legitimate drag is taking place
        handleDrag: function (dx, dy, ev) {
            this.trigger('drag', dx, dy, ev);
            this.updateAutoScroll(ev); // will possibly cause scrolling
        },
        endDrag: function (ev) {
            if (this.isDragging) {
                this.isDragging = false;
                this.handleDragEnd(ev);
            }
        },
        handleDragEnd: function (ev) {
            this.trigger('dragEnd', ev);
            this.destroyHrefHack();
        },
        // Delay
        // -----------------------------------------------------------------------------------------------------------------


        startDelay: function (initialEv) {
            var _this = this;

            if (this.delay) {
                this.delayTimeoutId = setTimeout(function () {
                    _this.handleDelayEnd(initialEv);
                }, this.delay);
            } else {
                this.handleDelayEnd(initialEv);
            }
        },
        handleDelayEnd: function (initialEv) {
            this.isDelayEnded = true;

            if (this.isDistanceSurpassed) {
                this.startDrag(initialEv);
            }
        },
        // Distance
        // -----------------------------------------------------------------------------------------------------------------


        handleDistanceSurpassed: function (ev) {
            this.isDistanceSurpassed = true;

            if (this.isDelayEnded) {
                this.startDrag(ev);
            }
        },
        // Mouse / Touch
        // -----------------------------------------------------------------------------------------------------------------


        handleTouchMove: function (ev) {
            // prevent inertia and touchmove-scrolling while dragging
            if (this.isDragging) {
                ev.preventDefault();
            }

            this.handleMove(ev);
        },
        handleMouseMove: function (ev) {
            this.handleMove(ev);
        },
        // Scrolling (unrelated to auto-scroll)
        // -----------------------------------------------------------------------------------------------------------------


        handleTouchScroll: function (ev) {
            // if the drag is being initiated by touch, but a scroll happens before
            // the drag-initiating delay is over, cancel the drag
            if (!this.isDragging) {
                this.endInteraction(ev, true); // isCancelled=true
            }
        },
        // <A> HREF Hack
        // -----------------------------------------------------------------------------------------------------------------


        initHrefHack: function () {
            var subjectEl = this.subjectEl;

            // remove a mousedown'd <a>'s href so it is not visited (IE8 bug)
            if ((this.subjectHref = subjectEl ? subjectEl.attr('href') : null)) {
                subjectEl.removeAttr('href');
            }
        },
        destroyHrefHack: function () {
            var subjectEl = this.subjectEl;
            var subjectHref = this.subjectHref;

            // restore a mousedown'd <a>'s href (for IE8 bug)
            setTimeout(function () { // must be outside of the click's execution
                if (subjectHref) {
                    subjectEl.attr('href', subjectHref);
                }
            }, 0);
        },
        // Utils
        // -----------------------------------------------------------------------------------------------------------------


        // Triggers a callback. Calls a function in the option hash of the same name.
        // Arguments beyond the first `name` are forwarded on.
        trigger: function (name) {
            if (this.options[name]) {
                this.options[name].apply(this, Array.prototype.slice.call(arguments, 1));
            }
            // makes _methods callable by event name. TODO: kill this
            if (this['_' + name]) {
                this['_' + name].apply(this, Array.prototype.slice.call(arguments, 1));
            }
        }


    });

    ;
    ;
    /*
     this.scrollEl is set in DragListener
     */
    DragListener.mixin({
        isAutoScroll: false,
        scrollBounds: null, // { top, bottom, left, right }
        scrollTopVel: null, // pixels per second
        scrollLeftVel: null, // pixels per second
        scrollIntervalId: null, // ID of setTimeout for scrolling animation loop

        // defaults
        scrollSensitivity: 30, // pixels from edge for scrolling to start
        scrollSpeed: 200, // pixels per second, at maximum speed
        scrollIntervalMs: 50, // millisecond wait between scroll increment


        initAutoScroll: function () {
            var scrollEl = this.scrollEl;

            this.isAutoScroll =
                    this.options.scroll &&
                    scrollEl &&
                    !scrollEl.is(window) &&
                    !scrollEl.is(document);

            if (this.isAutoScroll) {
                // debounce makes sure rapid calls don't happen
                this.listenTo(scrollEl, 'scroll', debounce(this.handleDebouncedScroll, 100));
            }
        },
        destroyAutoScroll: function () {
            this.endAutoScroll(); // kill any animation loop

            // remove the scroll handler if there is a scrollEl
            if (this.isAutoScroll) {
                this.stopListeningTo(this.scrollEl, 'scroll'); // will probably get removed by unbindHandlers too :(
            }
        },
        // Computes and stores the bounding rectangle of scrollEl
        computeScrollBounds: function () {
            if (this.isAutoScroll) {
                this.scrollBounds = getOuterRect(this.scrollEl);
                // TODO: use getClientRect in future. but prevents auto scrolling when on top of scrollbars
            }
        },
        // Called when the dragging is in progress and scrolling should be updated
        updateAutoScroll: function (ev) {
            var sensitivity = this.scrollSensitivity;
            var bounds = this.scrollBounds;
            var topCloseness, bottomCloseness;
            var leftCloseness, rightCloseness;
            var topVel = 0;
            var leftVel = 0;

            if (bounds) { // only scroll if scrollEl exists

                // compute closeness to edges. valid range is from 0.0 - 1.0
                topCloseness = (sensitivity - (getEvY(ev) - bounds.top)) / sensitivity;
                bottomCloseness = (sensitivity - (bounds.bottom - getEvY(ev))) / sensitivity;
                leftCloseness = (sensitivity - (getEvX(ev) - bounds.left)) / sensitivity;
                rightCloseness = (sensitivity - (bounds.right - getEvX(ev))) / sensitivity;

                // translate vertical closeness into velocity.
                // mouse must be completely in bounds for velocity to happen.
                if (topCloseness >= 0 && topCloseness <= 1) {
                    topVel = topCloseness * this.scrollSpeed * -1; // negative. for scrolling up
                } else if (bottomCloseness >= 0 && bottomCloseness <= 1) {
                    topVel = bottomCloseness * this.scrollSpeed;
                }

                // translate horizontal closeness into velocity
                if (leftCloseness >= 0 && leftCloseness <= 1) {
                    leftVel = leftCloseness * this.scrollSpeed * -1; // negative. for scrolling left
                } else if (rightCloseness >= 0 && rightCloseness <= 1) {
                    leftVel = rightCloseness * this.scrollSpeed;
                }
            }

            this.setScrollVel(topVel, leftVel);
        },
        // Sets the speed-of-scrolling for the scrollEl
        setScrollVel: function (topVel, leftVel) {

            this.scrollTopVel = topVel;
            this.scrollLeftVel = leftVel;

            this.constrainScrollVel(); // massages into realistic values

            // if there is non-zero velocity, and an animation loop hasn't already started, then START
            if ((this.scrollTopVel || this.scrollLeftVel) && !this.scrollIntervalId) {
                this.scrollIntervalId = setInterval(
                        proxy(this, 'scrollIntervalFunc'), // scope to `this`
                        this.scrollIntervalMs
                        );
            }
        },
        // Forces scrollTopVel and scrollLeftVel to be zero if scrolling has already gone all the way
        constrainScrollVel: function () {
            var el = this.scrollEl;

            if (this.scrollTopVel < 0) { // scrolling up?
                if (el.scrollTop() <= 0) { // already scrolled all the way up?
                    this.scrollTopVel = 0;
                }
            } else if (this.scrollTopVel > 0) { // scrolling down?
                if (el.scrollTop() + el[0].clientHeight >= el[0].scrollHeight) { // already scrolled all the way down?
                    this.scrollTopVel = 0;
                }
            }

            if (this.scrollLeftVel < 0) { // scrolling left?
                if (el.scrollLeft() <= 0) { // already scrolled all the left?
                    this.scrollLeftVel = 0;
                }
            } else if (this.scrollLeftVel > 0) { // scrolling right?
                if (el.scrollLeft() + el[0].clientWidth >= el[0].scrollWidth) { // already scrolled all the way right?
                    this.scrollLeftVel = 0;
                }
            }
        },
        // This function gets called during every iteration of the scrolling animation loop
        scrollIntervalFunc: function () {
            var el = this.scrollEl;
            var frac = this.scrollIntervalMs / 1000; // considering animation frequency, what the vel should be mult'd by

            // change the value of scrollEl's scroll
            if (this.scrollTopVel) {
                el.scrollTop(el.scrollTop() + this.scrollTopVel * frac);
            }
            if (this.scrollLeftVel) {
                el.scrollLeft(el.scrollLeft() + this.scrollLeftVel * frac);
            }

            this.constrainScrollVel(); // since the scroll values changed, recompute the velocities

            // if scrolled all the way, which causes the vels to be zero, stop the animation loop
            if (!this.scrollTopVel && !this.scrollLeftVel) {
                this.endAutoScroll();
            }
        },
        // Kills any existing scrolling animation loop
        endAutoScroll: function () {
            if (this.scrollIntervalId) {
                clearInterval(this.scrollIntervalId);
                this.scrollIntervalId = null;

                this.handleScrollEnd();
            }
        },
        // Get called when the scrollEl is scrolled (NOTE: this is delayed via debounce)
        handleDebouncedScroll: function () {
            // recompute all coordinates, but *only* if this is *not* part of our scrolling animation
            if (!this.scrollIntervalId) {
                this.handleScrollEnd();
            }
        },
        // Called when scrolling has stopped, whether through auto scroll, or the user scrolling
        handleScrollEnd: function () {
        }

    });
    ;
    ;

    /* Tracks mouse movements over a component and raises events about which hit the mouse is over.
     ------------------------------------------------------------------------------------------------------------------------
     options:
     - subjectEl
     - subjectCenter
     */

    var HitDragListener = DragListener.extend({
        component: null, // converts coordinates to hits
        // methods: prepareHits, releaseHits, queryHit

        origHit: null, // the hit the mouse was over when listening started
        hit: null, // the hit the mouse is over
        coordAdjust: null, // delta that will be added to the mouse coordinates when computing collisions


        constructor: function (component, options) {
            DragListener.call(this, options); // call the super-constructor

            this.component = component;
        },
        // Called when drag listening starts (but a real drag has not necessarily began).
        // ev might be undefined if dragging was started manually.
        handleInteractionStart: function (ev) {
            var subjectEl = this.subjectEl;
            var subjectRect;
            var origPoint;
            var point;

            this.computeCoords();

            if (ev) {
                origPoint = {left: getEvX(ev), top: getEvY(ev)};
                point = origPoint;

                // constrain the point to bounds of the element being dragged
                if (subjectEl) {
                    subjectRect = getOuterRect(subjectEl); // used for centering as well
                    point = constrainPoint(point, subjectRect);
                }

                this.origHit = this.queryHit(point.left, point.top);

                // treat the center of the subject as the collision point?
                if (subjectEl && this.options.subjectCenter) {

                    // only consider the area the subject overlaps the hit. best for large subjects.
                    // TODO: skip this if hit didn't supply left/right/top/bottom
                    if (this.origHit) {
                        subjectRect = intersectRects(this.origHit, subjectRect) ||
                                subjectRect; // in case there is no intersection
                    }

                    point = getRectCenter(subjectRect);
                }

                this.coordAdjust = diffPoints(point, origPoint); // point - origPoint
            } else {
                this.origHit = null;
                this.coordAdjust = null;
            }

            // call the super-method. do it after origHit has been computed
            DragListener.prototype.handleInteractionStart.apply(this, arguments);
        },
        // Recomputes the drag-critical positions of elements
        computeCoords: function () {
            this.component.prepareHits();
            this.computeScrollBounds(); // why is this here??????
        },
        // Called when the actual drag has started
        handleDragStart: function (ev) {
            var hit;

            DragListener.prototype.handleDragStart.apply(this, arguments); // call the super-method

            // might be different from this.origHit if the min-distance is large
            hit = this.queryHit(getEvX(ev), getEvY(ev));

            // report the initial hit the mouse is over
            // especially important if no min-distance and drag starts immediately
            if (hit) {
                this.handleHitOver(hit);
            }
        },
        // Called when the drag moves
        handleDrag: function (dx, dy, ev) {
            var hit;

            DragListener.prototype.handleDrag.apply(this, arguments); // call the super-method

            hit = this.queryHit(getEvX(ev), getEvY(ev));

            if (!isHitsEqual(hit, this.hit)) { // a different hit than before?
                if (this.hit) {
                    this.handleHitOut();
                }
                if (hit) {
                    this.handleHitOver(hit);
                }
            }
        },
        // Called when dragging has been stopped
        handleDragEnd: function () {
            this.handleHitDone();
            DragListener.prototype.handleDragEnd.apply(this, arguments); // call the super-method
        },
        // Called when a the mouse has just moved over a new hit
        handleHitOver: function (hit) {
            var isOrig = isHitsEqual(hit, this.origHit);

            this.hit = hit;

            this.trigger('hitOver', this.hit, isOrig, this.origHit);
        },
        // Called when the mouse has just moved out of a hit
        handleHitOut: function () {
            if (this.hit) {
                this.trigger('hitOut', this.hit);
                this.handleHitDone();
                this.hit = null;
            }
        },
        // Called after a hitOut. Also called before a dragStop
        handleHitDone: function () {
            if (this.hit) {
                this.trigger('hitDone', this.hit);
            }
        },
        // Called when the interaction ends, whether there was a real drag or not
        handleInteractionEnd: function () {
            DragListener.prototype.handleInteractionEnd.apply(this, arguments); // call the super-method

            this.origHit = null;
            this.hit = null;

            this.component.releaseHits();
        },
        // Called when scrolling has stopped, whether through auto scroll, or the user scrolling
        handleScrollEnd: function () {
            DragListener.prototype.handleScrollEnd.apply(this, arguments); // call the super-method

            this.computeCoords(); // hits' absolute positions will be in new places. recompute
        },
        // Gets the hit underneath the coordinates for the given mouse event
        queryHit: function (left, top) {

            if (this.coordAdjust) {
                left += this.coordAdjust.left;
                top += this.coordAdjust.top;
            }

            return this.component.queryHit(left, top);
        }

    });


// Returns `true` if the hits are identically equal. `false` otherwise. Must be from the same component.
// Two null values will be considered equal, as two "out of the component" states are the same.
    function isHitsEqual(hit0, hit1) {

        if (!hit0 && !hit1) {
            return true;
        }

        if (hit0 && hit1) {
            return hit0.component === hit1.component &&
                    isHitPropsWithin(hit0, hit1) &&
                    isHitPropsWithin(hit1, hit0); // ensures all props are identical
        }

        return false;
    }


// Returns true if all of subHit's non-standard properties are within superHit
    function isHitPropsWithin(subHit, superHit) {
        for (var propName in subHit) {
            if (!/^(component|left|right|top|bottom)$/.test(propName)) {
                if (subHit[propName] !== superHit[propName]) {
                    return false;
                }
            }
        }
        return true;
    }

    ;
    ;

    /* Creates a clone of an element and lets it track the mouse as it moves
     ----------------------------------------------------------------------------------------------------------------------*/

    var MouseFollower = Class.extend(ListenerMixin, {
        options: null,
        sourceEl: null, // the element that will be cloned and made to look like it is dragging
        el: null, // the clone of `sourceEl` that will track the mouse
        parentEl: null, // the element that `el` (the clone) will be attached to

        // the initial position of el, relative to the offset parent. made to match the initial offset of sourceEl
        top0: null,
        left0: null,
        // the absolute coordinates of the initiating touch/mouse action
        y0: null,
        x0: null,
        // the number of pixels the mouse has moved from its initial position
        topDelta: null,
        leftDelta: null,
        isFollowing: false,
        isHidden: false,
        isAnimating: false, // doing the revert animation?

        constructor: function (sourceEl, options) {
            this.options = options = options || {};
            this.sourceEl = sourceEl;
            this.parentEl = options.parentEl ? $(options.parentEl) : sourceEl.parent(); // default to sourceEl's parent
        },
        // Causes the element to start following the mouse
        start: function (ev) {
            if (!this.isFollowing) {
                this.isFollowing = true;

                this.y0 = getEvY(ev);
                this.x0 = getEvX(ev);
                this.topDelta = 0;
                this.leftDelta = 0;

                if (!this.isHidden) {
                    this.updatePosition();
                }

                if (getEvIsTouch(ev)) {
                    this.listenTo($(document), 'touchmove', this.handleMove);
                } else {
                    this.listenTo($(document), 'mousemove', this.handleMove);
                }
            }
        },
        // Causes the element to stop following the mouse. If shouldRevert is true, will animate back to original position.
        // `callback` gets invoked when the animation is complete. If no animation, it is invoked immediately.
        stop: function (shouldRevert, callback) {
            var _this = this;
            var revertDuration = this.options.revertDuration;

            function complete() {
                this.isAnimating = false;
                _this.removeElement();

                this.top0 = this.left0 = null; // reset state for future updatePosition calls

                if (callback) {
                    callback();
                }
            }

            if (this.isFollowing && !this.isAnimating) { // disallow more than one stop animation at a time
                this.isFollowing = false;

                this.stopListeningTo($(document));

                if (shouldRevert && revertDuration && !this.isHidden) { // do a revert animation?
                    this.isAnimating = true;
                    this.el.animate({
                        top: this.top0,
                        left: this.left0
                    }, {
                        duration: revertDuration,
                        complete: complete
                    });
                } else {
                    complete();
                }
            }
        },
        // Gets the tracking element. Create it if necessary
        getEl: function () {
            var el = this.el;

            if (!el) {
                this.sourceEl.width(); // hack to force IE8 to compute correct bounding box
                el = this.el = this.sourceEl.clone()
                        .addClass(this.options.additionalClass || '')
                        .css({
                            position: 'absolute',
                            visibility: '', // in case original element was hidden (commonly through hideEvents())
                            display: this.isHidden ? 'none' : '', // for when initially hidden
                            margin: 0,
                            right: 'auto', // erase and set width instead
                            bottom: 'auto', // erase and set height instead
                            width: this.sourceEl.width(), // explicit height in case there was a 'right' value
                            height: this.sourceEl.height(), // explicit width in case there was a 'bottom' value
                            opacity: this.options.opacity || '',
                            zIndex: this.options.zIndex
                        });

                // we don't want long taps or any mouse interaction causing selection/menus.
                // would use preventSelection(), but that prevents selectstart, causing problems.
                el.addClass('fc-unselectable');

                el.appendTo(this.parentEl);
            }

            return el;
        },
        // Removes the tracking element if it has already been created
        removeElement: function () {
            if (this.el) {
                this.el.remove();
                this.el = null;
            }
        },
        // Update the CSS position of the tracking element
        updatePosition: function () {
            var sourceOffset;
            var origin;

            this.getEl(); // ensure this.el

            // make sure origin info was computed
            if (this.top0 === null) {
                this.sourceEl.width(); // hack to force IE8 to compute correct bounding box
                sourceOffset = this.sourceEl.offset();
                origin = this.el.offsetParent().offset();
                this.top0 = sourceOffset.top - origin.top;
                this.left0 = sourceOffset.left - origin.left;
            }

            this.el.css({
                top: this.top0 + this.topDelta,
                left: this.left0 + this.leftDelta
            });
        },
        // Gets called when the user moves the mouse
        handleMove: function (ev) {
            this.topDelta = getEvY(ev) - this.y0;
            this.leftDelta = getEvX(ev) - this.x0;

            if (!this.isHidden) {
                this.updatePosition();
            }
        },
        // Temporarily makes the tracking element invisible. Can be called before following starts
        hide: function () {
            if (!this.isHidden) {
                this.isHidden = true;
                if (this.el) {
                    this.el.hide();
                }
            }
        },
        // Show the tracking element after it has been temporarily hidden
        show: function () {
            if (this.isHidden) {
                this.isHidden = false;
                this.updatePosition();
                this.getEl().show();
            }
        }

    });

    ;
    ;

    /* An abstract class comprised of a "grid" of areas that each represent a specific datetime
     ----------------------------------------------------------------------------------------------------------------------*/

    var Grid = FC.Grid = Class.extend(ListenerMixin, MouseIgnorerMixin, {
        view: null, // a View object
        isRTL: null, // shortcut to the view's isRTL option

        start: null,
        end: null,
        el: null, // the containing element
        elsByFill: null, // a hash of jQuery element sets used for rendering each fill. Keyed by fill name.

        // derived from options
        eventTimeFormat: null,
        displayEventTime: null,
        displayEventEnd: null,
        minResizeDuration: null, // TODO: hack. set by subclasses. minumum event resize duration

        // if defined, holds the unit identified (ex: "year" or "month") that determines the level of granularity
        // of the date areas. if not defined, assumes to be day and time granularity.
        // TODO: port isTimeScale into same system?
        largeUnit: null,
        dayDragListener: null,
        segDragListener: null,
        segResizeListener: null,
        externalDragListener: null,
        constructor: function (view) {
            this.view = view;
            this.isRTL = view.opt('isRTL');
            this.elsByFill = {};

            this.dayDragListener = this.buildDayDragListener();
            this.initMouseIgnoring();
        },
        /* Options
         ------------------------------------------------------------------------------------------------------------------*/


        // Generates the format string used for event time text, if not explicitly defined by 'timeFormat'
        computeEventTimeFormat: function () {
            return this.view.opt('smallTimeFormat');
        },
        // Determines whether events should have their end times displayed, if not explicitly defined by 'displayEventTime'.
        // Only applies to non-all-day events.
        computeDisplayEventTime: function () {
            return true;
        },
        // Determines whether events should have their end times displayed, if not explicitly defined by 'displayEventEnd'
        computeDisplayEventEnd: function () {
            return true;
        },
        /* Dates
         ------------------------------------------------------------------------------------------------------------------*/


        // Tells the grid about what period of time to display.
        // Any date-related internal data should be generated.
        setRange: function (range) {
            this.start = range.start.clone();
            this.end = range.end.clone();

            this.rangeUpdated();
            this.processRangeOptions();
        },
        // Called when internal variables that rely on the range should be updated
        rangeUpdated: function () {
        },
        // Updates values that rely on options and also relate to range
        processRangeOptions: function () {
            var view = this.view;
            var displayEventTime;
            var displayEventEnd;

            this.eventTimeFormat =
                    view.opt('eventTimeFormat') ||
                    view.opt('timeFormat') || // deprecated
                    this.computeEventTimeFormat();

            displayEventTime = view.opt('displayEventTime');
            if (displayEventTime == null) {
                displayEventTime = this.computeDisplayEventTime(); // might be based off of range
            }

            displayEventEnd = view.opt('displayEventEnd');
            if (displayEventEnd == null) {
                displayEventEnd = this.computeDisplayEventEnd(); // might be based off of range
            }

            this.displayEventTime = displayEventTime;
            this.displayEventEnd = displayEventEnd;
        },
        // Converts a span (has unzoned start/end and any other grid-specific location information)
        // into an array of segments (pieces of events whose format is decided by the grid).
        spanToSegs: function (span) {
            // subclasses must implement
        },
        // Diffs the two dates, returning a duration, based on granularity of the grid
        // TODO: port isTimeScale into this system?
        diffDates: function (a, b) {
            if (this.largeUnit) {
                return diffByUnit(a, b, this.largeUnit);
            } else {
                return diffDayTime(a, b);
            }
        },
        /* Hit Area
         ------------------------------------------------------------------------------------------------------------------*/


        // Called before one or more queryHit calls might happen. Should prepare any cached coordinates for queryHit
        prepareHits: function () {
        },
        // Called when queryHit calls have subsided. Good place to clear any coordinate caches.
        releaseHits: function () {
        },
        // Given coordinates from the topleft of the document, return data about the date-related area underneath.
        // Can return an object with arbitrary properties (although top/right/left/bottom are encouraged).
        // Must have a `grid` property, a reference to this current grid. TODO: avoid this
        // The returned object will be processed by getHitSpan and getHitEl.
        queryHit: function (leftOffset, topOffset) {
        },
        // Given position-level information about a date-related area within the grid,
        // should return an object with at least a start/end date. Can provide other information as well.
        getHitSpan: function (hit) {
        },
        // Given position-level information about a date-related area within the grid,
        // should return a jQuery element that best represents it. passed to dayClick callback.
        getHitEl: function (hit) {
        },
        /* Rendering
         ------------------------------------------------------------------------------------------------------------------*/


        // Sets the container element that the grid should render inside of.
        // Does other DOM-related initializations.
        setElement: function (el) {
            this.el = el;
            preventSelection(el);

            this.bindDayHandler('touchstart', this.dayTouchStart);
            this.bindDayHandler('mousedown', this.dayMousedown);

            // attach event-element-related handlers. in Grid.events
            // same garbage collection note as above.
            this.bindSegHandlers();

            this.bindGlobalHandlers();
        },
        bindDayHandler: function (name, handler) {
            var _this = this;

            // attach a handler to the grid's root element.
            // jQuery will take care of unregistering them when removeElement gets called.
            this.el.on(name, function (ev) {
                if (
                        !$(ev.target).is('.fc-event-container *, .fc-more') && // not an an event element, or "more.." link
                        !$(ev.target).closest('.fc-popover').length // not on a popover (like the "more.." events one)
                        ) {
                    return handler.call(_this, ev);
                }
            });
        },
        // Removes the grid's container element from the DOM. Undoes any other DOM-related attachments.
        // DOES NOT remove any content beforehand (doesn't clear events or call unrenderDates), unlike View
        removeElement: function () {
            this.unbindGlobalHandlers();
            this.clearDragListeners();

            this.el.remove();

            // NOTE: we don't null-out this.el for the same reasons we don't do it within View::removeElement
        },
        // Renders the basic structure of grid view before any content is rendered
        renderSkeleton: function () {
            // subclasses should implement
        },
        // Renders the grid's date-related content (like areas that represent days/times).
        // Assumes setRange has already been called and the skeleton has already been rendered.
        renderDates: function () {
            // subclasses should implement
        },
        // Unrenders the grid's date-related content
        unrenderDates: function () {
            // subclasses should implement
        },
        /* Handlers
         ------------------------------------------------------------------------------------------------------------------*/


        // Binds DOM handlers to elements that reside outside the grid, such as the document
        bindGlobalHandlers: function () {
            this.listenTo($(document), {
                dragstart: this.externalDragStart, // jqui
                sortstart: this.externalDragStart // jqui
            });
        },
        // Unbinds DOM handlers from elements that reside outside the grid
        unbindGlobalHandlers: function () {
            this.stopListeningTo($(document));
        },
        // Process a mousedown on an element that represents a day. For day clicking and selecting.
        dayMousedown: function (ev) {
            if (!this.isIgnoringMouse) {
                this.dayDragListener.startInteraction(ev, {
                    //distance: 5, // needs more work if we want dayClick to fire correctly
                });
            }
        },
        dayTouchStart: function (ev) {
            var view = this.view;

            // HACK to prevent a user's clickaway for unselecting a range or an event
            // from causing a dayClick.
            if (view.isSelected || view.selectedEvent) {
                this.tempIgnoreMouse();
            }

            this.dayDragListener.startInteraction(ev, {
                delay: this.view.opt('longPressDelay')
            });
        },
        // Creates a listener that tracks the user's drag across day elements.
        // For day clicking and selecting.
        buildDayDragListener: function () {
            var _this = this;
            var view = this.view;
            var isSelectable = view.opt('selectable');
            var dayClickHit; // null if invalid dayClick
            var selectionSpan; // null if invalid selection

            // this listener tracks a mousedown on a day element, and a subsequent drag.
            // if the drag ends on the same day, it is a 'dayClick'.
            // if 'selectable' is enabled, this listener also detects selections.
            var dragListener = new HitDragListener(this, {
                scroll: view.opt('dragScroll'),
                interactionStart: function () {
                    dayClickHit = dragListener.origHit; // for dayClick, where no dragging happens
                },
                dragStart: function () {
                    view.unselect(); // since we could be rendering a new selection, we want to clear any old one
                },
                hitOver: function (hit, isOrig, origHit) {
                    if (origHit) { // click needs to have started on a hit

                        // if user dragged to another cell at any point, it can no longer be a dayClick
                        if (!isOrig) {
                            dayClickHit = null;
                        }

                        if (isSelectable) {
                            selectionSpan = _this.computeSelection(
                                    _this.getHitSpan(origHit),
                                    _this.getHitSpan(hit)
                                    );
                            if (selectionSpan) {
                                _this.renderSelection(selectionSpan);
                            } else if (selectionSpan === false) {
                                disableCursor();
                            }
                        }
                    }
                },
                hitOut: function () {
                    dayClickHit = null;
                    selectionSpan = null;
                    _this.unrenderSelection();
                    enableCursor();
                },
                interactionEnd: function (ev, isCancelled) {
                    if (!isCancelled) {
                        if (
                                dayClickHit &&
                                !_this.isIgnoringMouse // see hack in dayTouchStart
                                ) {
                            view.triggerDayClick(
                                    _this.getHitSpan(dayClickHit),
                                    _this.getHitEl(dayClickHit),
                                    ev
                                    );
                        }
                        if (selectionSpan) {
                            // the selection will already have been rendered. just report it
                            view.reportSelection(selectionSpan, ev);
                        }
                        enableCursor();
                    }
                }
            });

            return dragListener;
        },
        // Kills all in-progress dragging.
        // Useful for when public API methods that result in re-rendering are invoked during a drag.
        // Also useful for when touch devices misbehave and don't fire their touchend.
        clearDragListeners: function () {
            this.dayDragListener.endInteraction();

            if (this.segDragListener) {
                this.segDragListener.endInteraction(); // will clear this.segDragListener
            }
            if (this.segResizeListener) {
                this.segResizeListener.endInteraction(); // will clear this.segResizeListener
            }
            if (this.externalDragListener) {
                this.externalDragListener.endInteraction(); // will clear this.externalDragListener
            }
        },
        /* Event Helper
         ------------------------------------------------------------------------------------------------------------------*/
        // TODO: should probably move this to Grid.events, like we did event dragging / resizing


        // Renders a mock event at the given event location, which contains zoned start/end properties.
        // Returns all mock event elements.
        renderEventLocationHelper: function (eventLocation, sourceSeg) {
            var fakeEvent = this.fabricateHelperEvent(eventLocation, sourceSeg);

            return this.renderHelper(fakeEvent, sourceSeg); // do the actual rendering
        },
        // Builds a fake event given zoned event date properties and a segment is should be inspired from.
        // The range's end can be null, in which case the mock event that is rendered will have a null end time.
        // `sourceSeg` is the internal segment object involved in the drag. If null, something external is dragging.
        fabricateHelperEvent: function (eventLocation, sourceSeg) {
            var fakeEvent = sourceSeg ? createObject(sourceSeg.event) : {}; // mask the original event object if possible

            fakeEvent.start = eventLocation.start.clone();
            fakeEvent.end = eventLocation.end ? eventLocation.end.clone() : null;
            fakeEvent.allDay = null; // force it to be freshly computed by normalizeEventDates
            this.view.calendar.normalizeEventDates(fakeEvent);

            // this extra className will be useful for differentiating real events from mock events in CSS
            fakeEvent.className = (fakeEvent.className || []).concat('fc-helper');

            // if something external is being dragged in, don't render a resizer
            if (!sourceSeg) {
                fakeEvent.editable = false;
            }

            return fakeEvent;
        },
        // Renders a mock event. Given zoned event date properties.
        // Must return all mock event elements.
        renderHelper: function (eventLocation, sourceSeg) {
            // subclasses must implement
        },
        // Unrenders a mock event
        unrenderHelper: function () {
            // subclasses must implement
        },
        /* Selection
         ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of a selection. Will highlight by default but can be overridden by subclasses.
        // Given a span (unzoned start/end and other misc data)
        renderSelection: function (span) {
            this.renderHighlight(span);
        },
        // Unrenders any visual indications of a selection. Will unrender a highlight by default.
        unrenderSelection: function () {
            this.unrenderHighlight();
        },
        // Given the first and last date-spans of a selection, returns another date-span object.
        // Subclasses can override and provide additional data in the span object. Will be passed to renderSelection().
        // Will return false if the selection is invalid and this should be indicated to the user.
        // Will return null/undefined if a selection invalid but no error should be reported.
        computeSelection: function (span0, span1) {
            var span = this.computeSelectionSpan(span0, span1);

            if (span && !this.view.calendar.isSelectionSpanAllowed(span)) {
                return false;
            }

            return span;
        },
        // Given two spans, must return the combination of the two.
        // TODO: do this separation of concerns (combining VS validation) for event dnd/resize too.
        computeSelectionSpan: function (span0, span1) {
            var dates = [span0.start, span0.end, span1.start, span1.end];

            dates.sort(compareNumbers); // sorts chronologically. works with Moments

            return {start: dates[0].clone(), end: dates[3].clone()};
        },
        /* Highlight
         ------------------------------------------------------------------------------------------------------------------*/


        // Renders an emphasis on the given date range. Given a span (unzoned start/end and other misc data)
        renderHighlight: function (span) {
            this.renderFill('highlight', this.spanToSegs(span));
        },
        // Unrenders the emphasis on a date range
        unrenderHighlight: function () {
            this.unrenderFill('highlight');
        },
        // Generates an array of classNames for rendering the highlight. Used by the fill system.
        highlightSegClasses: function () {
            return ['fc-highlight'];
        },
        /* Business Hours
         ------------------------------------------------------------------------------------------------------------------*/


        renderBusinessHours: function () {
        },
        unrenderBusinessHours: function () {
        },
        /* Now Indicator
         ------------------------------------------------------------------------------------------------------------------*/


        getNowIndicatorUnit: function () {
        },
        renderNowIndicator: function (date) {
        },
        unrenderNowIndicator: function () {
        },
        /* Fill System (highlight, background events, business hours)
         --------------------------------------------------------------------------------------------------------------------
         TODO: remove this system. like we did in TimeGrid
         */


        // Renders a set of rectangles over the given segments of time.
        // MUST RETURN a subset of segs, the segs that were actually rendered.
        // Responsible for populating this.elsByFill. TODO: better API for expressing this requirement
        renderFill: function (type, segs) {
            // subclasses must implement
        },
        // Unrenders a specific type of fill that is currently rendered on the grid
        unrenderFill: function (type) {
            var el = this.elsByFill[type];

            if (el) {
                el.remove();
                delete this.elsByFill[type];
            }
        },
        // Renders and assigns an `el` property for each fill segment. Generic enough to work with different types.
        // Only returns segments that successfully rendered.
        // To be harnessed by renderFill (implemented by subclasses).
        // Analagous to renderFgSegEls.
        renderFillSegEls: function (type, segs) {
            var _this = this;
            var segElMethod = this[type + 'SegEl'];
            var html = '';
            var renderedSegs = [];
            var i;

            if (segs.length) {

                // build a large concatenation of segment HTML
                for (i = 0; i < segs.length; i++) {
                    html += this.fillSegHtml(type, segs[i]);
                }

                // Grab individual elements from the combined HTML string. Use each as the default rendering.
                // Then, compute the 'el' for each segment.
                $(html).each(function (i, node) {
                    var seg = segs[i];
                    var el = $(node);

                    // allow custom filter methods per-type
                    if (segElMethod) {
                        el = segElMethod.call(_this, seg, el);
                    }

                    if (el) { // custom filters did not cancel the render
                        el = $(el); // allow custom filter to return raw DOM node

                        // correct element type? (would be bad if a non-TD were inserted into a table for example)
                        if (el.is(_this.fillSegTag)) {
                            seg.el = el;
                            renderedSegs.push(seg);
                        }
                    }
                });
            }

            return renderedSegs;
        },
        fillSegTag: 'div', // subclasses can override


        // Builds the HTML needed for one fill segment. Generic enough to work with different types.
        fillSegHtml: function (type, seg) {

            // custom hooks per-type
            var classesMethod = this[type + 'SegClasses'];
            var cssMethod = this[type + 'SegCss'];

            var classes = classesMethod ? classesMethod.call(this, seg) : [];
            var css = cssToStr(cssMethod ? cssMethod.call(this, seg) : {});

            return '<' + this.fillSegTag +
                    (classes.length ? ' class="' + classes.join(' ') + '"' : '') +
                    (css ? ' style="' + css + '"' : '') +
                    ' />';
        },
        /* Generic rendering utilities for subclasses
         ------------------------------------------------------------------------------------------------------------------*/


        // Computes HTML classNames for a single-day element
        getDayClasses: function (date) {
            var view = this.view;
            var today = view.calendar.getNow();
            var classes = ['fc-' + dayIDs[date.day()]];

            if (
                    view.intervalDuration.as('months') == 1 &&
                    date.month() != view.intervalStart.month()
                    ) {
                classes.push('fc-other-month');
            }

            if (date.isSame(today, 'day')) {
                classes.push(
                        'fc-today',
                        view.highlightStateClass
                        );
            } else if (date < today) {
                classes.push('fc-past');
            } else {
                classes.push('fc-future');
            }

            return classes;
        }

    });

    ;
    ;

    /* Event-rendering and event-interaction methods for the abstract Grid class
     ----------------------------------------------------------------------------------------------------------------------*/

    Grid.mixin({
        mousedOverSeg: null, // the segment object the user's mouse is over. null if over nothing
        isDraggingSeg: false, // is a segment being dragged? boolean
        isResizingSeg: false, // is a segment being resized? boolean
        isDraggingExternal: false, // jqui-dragging an external element? boolean
        segs: null, // the *event* segments currently rendered in the grid. TODO: rename to `eventSegs`


        // Renders the given events onto the grid
        renderEvents: function (events) {
            var bgEvents = [];
            var fgEvents = [];
            var i;

            for (i = 0; i < events.length; i++) {
                (isBgEvent(events[i]) ? bgEvents : fgEvents).push(events[i]);
            }

            this.segs = [].concat(// record all segs
                    this.renderBgEvents(bgEvents),
                    this.renderFgEvents(fgEvents)
                    );
        },
        renderBgEvents: function (events) {
            var segs = this.eventsToSegs(events);

            // renderBgSegs might return a subset of segs, segs that were actually rendered
            return this.renderBgSegs(segs) || segs;
        },
        renderFgEvents: function (events) {
            var segs = this.eventsToSegs(events);

            // renderFgSegs might return a subset of segs, segs that were actually rendered
            return this.renderFgSegs(segs) || segs;
        },
        // Unrenders all events currently rendered on the grid
        unrenderEvents: function () {
            this.handleSegMouseout(); // trigger an eventMouseout if user's mouse is over an event
            this.clearDragListeners();

            this.unrenderFgSegs();
            this.unrenderBgSegs();

            this.segs = null;
        },
        // Retrieves all rendered segment objects currently rendered on the grid
        getEventSegs: function () {
            return this.segs || [];
        },
        /* Foreground Segment Rendering
         ------------------------------------------------------------------------------------------------------------------*/


        // Renders foreground event segments onto the grid. May return a subset of segs that were rendered.
        renderFgSegs: function (segs) {
            // subclasses must implement
        },
        // Unrenders all currently rendered foreground segments
        unrenderFgSegs: function () {
            // subclasses must implement
        },
        // Renders and assigns an `el` property for each foreground event segment.
        // Only returns segments that successfully rendered.
        // A utility that subclasses may use.
        renderFgSegEls: function (segs, disableResizing) {
            var view = this.view;
            var html = '';
            var renderedSegs = [];
            var i;

            if (segs.length) { // don't build an empty html string

                // build a large concatenation of event segment HTML
                for (i = 0; i < segs.length; i++) {
                    html += this.fgSegHtml(segs[i], disableResizing);
                }

                // Grab individual elements from the combined HTML string. Use each as the default rendering.
                // Then, compute the 'el' for each segment. An el might be null if the eventRender callback returned false.
                $(html).each(function (i, node) {
                    var seg = segs[i];
                    var el = view.resolveEventEl(seg.event, $(node));

                    if (el) {
                        el.data('fc-seg', seg); // used by handlers
                        seg.el = el;
                        renderedSegs.push(seg);
                    }
                });
            }

            return renderedSegs;
        },
        // Generates the HTML for the default rendering of a foreground event segment. Used by renderFgSegEls()
        fgSegHtml: function (seg, disableResizing) {
            // subclasses should implement
        },
        /* Background Segment Rendering
         ------------------------------------------------------------------------------------------------------------------*/


        // Renders the given background event segments onto the grid.
        // Returns a subset of the segs that were actually rendered.
        renderBgSegs: function (segs) {
            return this.renderFill('bgEvent', segs);
        },
        // Unrenders all the currently rendered background event segments
        unrenderBgSegs: function () {
            this.unrenderFill('bgEvent');
        },
        // Renders a background event element, given the default rendering. Called by the fill system.
        bgEventSegEl: function (seg, el) {
            return this.view.resolveEventEl(seg.event, el); // will filter through eventRender
        },
        // Generates an array of classNames to be used for the default rendering of a background event.
        // Called by the fill system.
        bgEventSegClasses: function (seg) {
            var event = seg.event;
            var source = event.source || {};

            return ['fc-bgevent'].concat(
                    event.className,
                    source.className || []
                    );
        },
        // Generates a semicolon-separated CSS string to be used for the default rendering of a background event.
        // Called by the fill system.
        bgEventSegCss: function (seg) {
            return {
                'background-color': this.getSegSkinCss(seg)['background-color']
            };
        },
        // Generates an array of classNames to be used for the rendering business hours overlay. Called by the fill system.
        businessHoursSegClasses: function (seg) {
            return ['fc-nonbusiness', 'fc-bgevent'];
        },
        /* Handlers
         ------------------------------------------------------------------------------------------------------------------*/


        // Attaches event-element-related handlers to the container element and leverage bubbling
        bindSegHandlers: function () {
            this.bindSegHandler('touchstart', this.handleSegTouchStart);
            this.bindSegHandler('touchend', this.handleSegTouchEnd);
            this.bindSegHandler('mouseenter', this.handleSegMouseover);
            this.bindSegHandler('mouseleave', this.handleSegMouseout);
            this.bindSegHandler('mousedown', this.handleSegMousedown);
            this.bindSegHandler('click', this.handleSegClick);
        },
        // Executes a handler for any a user-interaction on a segment.
        // Handler gets called with (seg, ev), and with the `this` context of the Grid
        bindSegHandler: function (name, handler) {
            var _this = this;

            this.el.on(name, '.fc-event-container > *', function (ev) {
                var seg = $(this).data('fc-seg'); // grab segment data. put there by View::renderEvents

                // only call the handlers if there is not a drag/resize in progress
                if (seg && !_this.isDraggingSeg && !_this.isResizingSeg) {
                    return handler.call(_this, seg, ev); // context will be the Grid
                }
            });
        },
        handleSegClick: function (seg, ev) {
            return this.view.trigger('eventClick', seg.el[0], seg.event, ev); // can return `false` to cancel
        },
        // Updates internal state and triggers handlers for when an event element is moused over
        handleSegMouseover: function (seg, ev) {
            if (
                    !this.isIgnoringMouse &&
                    !this.mousedOverSeg
                    ) {
                this.mousedOverSeg = seg;
                seg.el.addClass('fc-allow-mouse-resize');
                this.view.trigger('eventMouseover', seg.el[0], seg.event, ev);
            }
        },
        // Updates internal state and triggers handlers for when an event element is moused out.
        // Can be given no arguments, in which case it will mouseout the segment that was previously moused over.
        handleSegMouseout: function (seg, ev) {
            ev = ev || {}; // if given no args, make a mock mouse event

            if (this.mousedOverSeg) {
                seg = seg || this.mousedOverSeg; // if given no args, use the currently moused-over segment
                this.mousedOverSeg = null;
                seg.el.removeClass('fc-allow-mouse-resize');
                this.view.trigger('eventMouseout', seg.el[0], seg.event, ev);
            }
        },
        handleSegMousedown: function (seg, ev) {
            var isResizing = this.startSegResize(seg, ev, {distance: 5});

            if (!isResizing && this.view.isEventDraggable(seg.event)) {
                this.buildSegDragListener(seg)
                        .startInteraction(ev, {
                            distance: 5
                        });
            }
        },
        handleSegTouchStart: function (seg, ev) {
            var view = this.view;
            var event = seg.event;
            var isSelected = view.isEventSelected(event);
            var isDraggable = view.isEventDraggable(event);
            var isResizable = view.isEventResizable(event);
            var isResizing = false;
            var dragListener;

            if (isSelected && isResizable) {
                // only allow resizing of the event is selected
                isResizing = this.startSegResize(seg, ev);
            }

            if (!isResizing && (isDraggable || isResizable)) { // allowed to be selected?

                dragListener = isDraggable ?
                        this.buildSegDragListener(seg) :
                        this.buildSegSelectListener(seg); // seg isn't draggable, but still needs to be selected

                dragListener.startInteraction(ev, {// won't start if already started
                    delay: isSelected ? 0 : this.view.opt('longPressDelay') // do delay if not already selected
                });
            }

            // a long tap simulates a mouseover. ignore this bogus mouseover.
            this.tempIgnoreMouse();
        },
        handleSegTouchEnd: function (seg, ev) {
            // touchstart+touchend = click, which simulates a mouseover.
            // ignore this bogus mouseover.
            this.tempIgnoreMouse();
        },
        // returns boolean whether resizing actually started or not.
        // assumes the seg allows resizing.
        // `dragOptions` are optional.
        startSegResize: function (seg, ev, dragOptions) {
            if ($(ev.target).is('.fc-resizer')) {
                this.buildSegResizeListener(seg, $(ev.target).is('.fc-start-resizer'))
                        .startInteraction(ev, dragOptions);
                return true;
            }
            return false;
        },
        /* Event Dragging
         ------------------------------------------------------------------------------------------------------------------*/


        // Builds a listener that will track user-dragging on an event segment.
        // Generic enough to work with any type of Grid.
        // Has side effect of setting/unsetting `segDragListener`
        buildSegDragListener: function (seg) {
            var _this = this;
            var view = this.view;
            var calendar = view.calendar;
            var el = seg.el;
            var event = seg.event;
            var isDragging;
            var mouseFollower; // A clone of the original element that will move with the mouse
            var dropLocation; // zoned event date properties

            if (this.segDragListener) {
                return this.segDragListener;
            }

            // Tracks mouse movement over the *view's* coordinate map. Allows dragging and dropping between subcomponents
            // of the view.
            var dragListener = this.segDragListener = new HitDragListener(view, {
                scroll: view.opt('dragScroll'),
                subjectEl: el,
                subjectCenter: true,
                interactionStart: function (ev) {
                    isDragging = false;
                    mouseFollower = new MouseFollower(seg.el, {
                        additionalClass: 'fc-dragging',
                        parentEl: view.el,
                        opacity: dragListener.isTouch ? null : view.opt('dragOpacity'),
                        revertDuration: view.opt('dragRevertDuration'),
                        zIndex: 2 // one above the .fc-view
                    });
                    mouseFollower.hide(); // don't show until we know this is a real drag
                    mouseFollower.start(ev);
                },
                dragStart: function (ev) {
                    if (dragListener.isTouch && !view.isEventSelected(event)) {
                        // if not previously selected, will fire after a delay. then, select the event
                        view.selectEvent(event);
                    }
                    isDragging = true;
                    _this.handleSegMouseout(seg, ev); // ensure a mouseout on the manipulated event has been reported
                    _this.segDragStart(seg, ev);
                    view.hideEvent(event); // hide all event segments. our mouseFollower will take over
                },
                hitOver: function (hit, isOrig, origHit) {
                    var dragHelperEls;

                    // starting hit could be forced (DayGrid.limit)
                    if (seg.hit) {
                        origHit = seg.hit;
                    }

                    // since we are querying the parent view, might not belong to this grid
                    dropLocation = _this.computeEventDrop(
                            origHit.component.getHitSpan(origHit),
                            hit.component.getHitSpan(hit),
                            event
                            );

                    if (dropLocation && !calendar.isEventSpanAllowed(_this.eventToSpan(dropLocation), event)) {
                        disableCursor();
                        dropLocation = null;
                    }

                    // if a valid drop location, have the subclass render a visual indication
                    if (dropLocation && (dragHelperEls = view.renderDrag(dropLocation, seg))) {

                        dragHelperEls.addClass('fc-dragging');
                        if (!dragListener.isTouch) {
                            _this.applyDragOpacity(dragHelperEls);
                        }

                        mouseFollower.hide(); // if the subclass is already using a mock event "helper", hide our own
                    } else {
                        mouseFollower.show(); // otherwise, have the helper follow the mouse (no snapping)
                    }

                    if (isOrig) {
                        dropLocation = null; // needs to have moved hits to be a valid drop
                    }
                },
                hitOut: function () { // called before mouse moves to a different hit OR moved out of all hits
                    view.unrenderDrag(); // unrender whatever was done in renderDrag
                    mouseFollower.show(); // show in case we are moving out of all hits
                    dropLocation = null;
                },
                hitDone: function () { // Called after a hitOut OR before a dragEnd
                    enableCursor();
                },
                interactionEnd: function (ev) {
                    // do revert animation if hasn't changed. calls a callback when finished (whether animation or not)
                    mouseFollower.stop(!dropLocation, function () {
                        if (isDragging) {
                            view.unrenderDrag();
                            view.showEvent(event);
                            _this.segDragStop(seg, ev);
                        }
                        if (dropLocation) {
                            view.reportEventDrop(event, dropLocation, this.largeUnit, el, ev);
                        }
                    });
                    _this.segDragListener = null;
                }
            });

            return dragListener;
        },
        // seg isn't draggable, but let's use a generic DragListener
        // simply for the delay, so it can be selected.
        // Has side effect of setting/unsetting `segDragListener`
        buildSegSelectListener: function (seg) {
            var _this = this;
            var view = this.view;
            var event = seg.event;

            if (this.segDragListener) {
                return this.segDragListener;
            }

            var dragListener = this.segDragListener = new DragListener({
                dragStart: function (ev) {
                    if (dragListener.isTouch && !view.isEventSelected(event)) {
                        // if not previously selected, will fire after a delay. then, select the event
                        view.selectEvent(event);
                    }
                },
                interactionEnd: function (ev) {
                    _this.segDragListener = null;
                }
            });

            return dragListener;
        },
        // Called before event segment dragging starts
        segDragStart: function (seg, ev) {
            this.isDraggingSeg = true;
            this.view.trigger('eventDragStart', seg.el[0], seg.event, ev, {}); // last argument is jqui dummy
        },
        // Called after event segment dragging stops
        segDragStop: function (seg, ev) {
            this.isDraggingSeg = false;
            this.view.trigger('eventDragStop', seg.el[0], seg.event, ev, {}); // last argument is jqui dummy
        },
        // Given the spans an event drag began, and the span event was dropped, calculates the new zoned start/end/allDay
        // values for the event. Subclasses may override and set additional properties to be used by renderDrag.
        // A falsy returned value indicates an invalid drop.
        // DOES NOT consider overlap/constraint.
        computeEventDrop: function (startSpan, endSpan, event) {
            var calendar = this.view.calendar;
            var dragStart = startSpan.start;
            var dragEnd = endSpan.start;
            var delta;
            var dropLocation; // zoned event date properties

            if (dragStart.hasTime() === dragEnd.hasTime()) {
                delta = this.diffDates(dragEnd, dragStart);

                // if an all-day event was in a timed area and it was dragged to a different time,
                // guarantee an end and adjust start/end to have times
                if (event.allDay && durationHasTime(delta)) {
                    dropLocation = {
                        start: event.start.clone(),
                        end: calendar.getEventEnd(event), // will be an ambig day
                        allDay: false // for normalizeEventTimes
                    };
                    calendar.normalizeEventTimes(dropLocation);
                }
                // othewise, work off existing values
                else {
                    dropLocation = {
                        start: event.start.clone(),
                        end: event.end ? event.end.clone() : null,
                        allDay: event.allDay // keep it the same
                    };
                }

                dropLocation.start.add(delta);
                if (dropLocation.end) {
                    dropLocation.end.add(delta);
                }
            } else {
                // if switching from day <-> timed, start should be reset to the dropped date, and the end cleared
                dropLocation = {
                    start: dragEnd.clone(),
                    end: null, // end should be cleared
                    allDay: !dragEnd.hasTime()
                };
            }

            return dropLocation;
        },
        // Utility for apply dragOpacity to a jQuery set
        applyDragOpacity: function (els) {
            var opacity = this.view.opt('dragOpacity');

            if (opacity != null) {
                els.each(function (i, node) {
                    // Don't use jQuery (will set an IE filter), do it the old fashioned way.
                    // In IE8, a helper element will disappears if there's a filter.
                    node.style.opacity = opacity;
                });
            }
        },
        /* External Element Dragging
         ------------------------------------------------------------------------------------------------------------------*/


        // Called when a jQuery UI drag is initiated anywhere in the DOM
        externalDragStart: function (ev, ui) {
            var view = this.view;
            var el;
            var accept;

            if (view.opt('droppable')) { // only listen if this setting is on
                el = $((ui ? ui.item : null) || ev.target);

                // Test that the dragged element passes the dropAccept selector or filter function.
                // FYI, the default is "*" (matches all)
                accept = view.opt('dropAccept');
                if ($.isFunction(accept) ? accept.call(el[0], el) : el.is(accept)) {
                    if (!this.isDraggingExternal) { // prevent double-listening if fired twice
                        this.listenToExternalDrag(el, ev, ui);
                    }
                }
            }
        },
        // Called when a jQuery UI drag starts and it needs to be monitored for dropping
        listenToExternalDrag: function (el, ev, ui) {
            var _this = this;
            var calendar = this.view.calendar;
            var meta = getDraggedElMeta(el); // extra data about event drop, including possible event to create
            var dropLocation; // a null value signals an unsuccessful drag

            // listener that tracks mouse movement over date-associated pixel regions
            var dragListener = _this.externalDragListener = new HitDragListener(this, {
                interactionStart: function () {
                    _this.isDraggingExternal = true;
                },
                hitOver: function (hit) {
                    dropLocation = _this.computeExternalDrop(
                            hit.component.getHitSpan(hit), // since we are querying the parent view, might not belong to this grid
                            meta
                            );

                    if (// invalid hit?
                            dropLocation &&
                            !calendar.isExternalSpanAllowed(_this.eventToSpan(dropLocation), dropLocation, meta.eventProps)
                            ) {
                        disableCursor();
                        dropLocation = null;
                    }

                    if (dropLocation) {
                        _this.renderDrag(dropLocation); // called without a seg parameter
                    }
                },
                hitOut: function () {
                    dropLocation = null; // signal unsuccessful
                },
                hitDone: function () { // Called after a hitOut OR before a dragEnd
                    enableCursor();
                    _this.unrenderDrag();
                },
                interactionEnd: function (ev) {
                    if (dropLocation) { // element was dropped on a valid hit
                        _this.view.reportExternalDrop(meta, dropLocation, el, ev, ui);
                    }
                    _this.isDraggingExternal = false;
                    _this.externalDragListener = null;
                }
            });

            dragListener.startDrag(ev); // start listening immediately
        },
        // Given a hit to be dropped upon, and misc data associated with the jqui drag (guaranteed to be a plain object),
        // returns the zoned start/end dates for the event that would result from the hypothetical drop. end might be null.
        // Returning a null value signals an invalid drop hit.
        // DOES NOT consider overlap/constraint.
        computeExternalDrop: function (span, meta) {
            var calendar = this.view.calendar;
            var dropLocation = {
                start: calendar.applyTimezone(span.start), // simulate a zoned event start date
                end: null
            };

            // if dropped on an all-day span, and element's metadata specified a time, set it
            if (meta.startTime && !dropLocation.start.hasTime()) {
                dropLocation.start.time(meta.startTime);
            }

            if (meta.duration) {
                dropLocation.end = dropLocation.start.clone().add(meta.duration);
            }

            return dropLocation;
        },
        /* Drag Rendering (for both events and an external elements)
         ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of an event or external element being dragged.
        // `dropLocation` contains hypothetical start/end/allDay values the event would have if dropped. end can be null.
        // `seg` is the internal segment object that is being dragged. If dragging an external element, `seg` is null.
        // A truthy returned value indicates this method has rendered a helper element.
        // Must return elements used for any mock events.
        renderDrag: function (dropLocation, seg) {
            // subclasses must implement
        },
        // Unrenders a visual indication of an event or external element being dragged
        unrenderDrag: function () {
            // subclasses must implement
        },
        /* Resizing
         ------------------------------------------------------------------------------------------------------------------*/


        // Creates a listener that tracks the user as they resize an event segment.
        // Generic enough to work with any type of Grid.
        buildSegResizeListener: function (seg, isStart) {
            var _this = this;
            var view = this.view;
            var calendar = view.calendar;
            var el = seg.el;
            var event = seg.event;
            var eventEnd = calendar.getEventEnd(event);
            var isDragging;
            var resizeLocation; // zoned event date properties. falsy if invalid resize

            // Tracks mouse movement over the *grid's* coordinate map
            var dragListener = this.segResizeListener = new HitDragListener(this, {
                scroll: view.opt('dragScroll'),
                subjectEl: el,
                interactionStart: function () {
                    isDragging = false;
                },
                dragStart: function (ev) {
                    isDragging = true;
                    _this.handleSegMouseout(seg, ev); // ensure a mouseout on the manipulated event has been reported
                    _this.segResizeStart(seg, ev);
                },
                hitOver: function (hit, isOrig, origHit) {
                    var origHitSpan = _this.getHitSpan(origHit);
                    var hitSpan = _this.getHitSpan(hit);

                    resizeLocation = isStart ?
                            _this.computeEventStartResize(origHitSpan, hitSpan, event) :
                            _this.computeEventEndResize(origHitSpan, hitSpan, event);

                    if (resizeLocation) {
                        if (!calendar.isEventSpanAllowed(_this.eventToSpan(resizeLocation), event)) {
                            disableCursor();
                            resizeLocation = null;
                        }
                        // no change? (TODO: how does this work with timezones?)
                        else if (resizeLocation.start.isSame(event.start) && resizeLocation.end.isSame(eventEnd)) {
                            resizeLocation = null;
                        }
                    }

                    if (resizeLocation) {
                        view.hideEvent(event);
                        _this.renderEventResize(resizeLocation, seg);
                    }
                },
                hitOut: function () { // called before mouse moves to a different hit OR moved out of all hits
                    resizeLocation = null;
                },
                hitDone: function () { // resets the rendering to show the original event
                    _this.unrenderEventResize();
                    view.showEvent(event);
                    enableCursor();
                },
                interactionEnd: function (ev) {
                    if (isDragging) {
                        _this.segResizeStop(seg, ev);
                    }
                    if (resizeLocation) { // valid date to resize to?
                        view.reportEventResize(event, resizeLocation, this.largeUnit, el, ev);
                    }
                    _this.segResizeListener = null;
                }
            });

            return dragListener;
        },
        // Called before event segment resizing starts
        segResizeStart: function (seg, ev) {
            this.isResizingSeg = true;
            this.view.trigger('eventResizeStart', seg.el[0], seg.event, ev, {}); // last argument is jqui dummy
        },
        // Called after event segment resizing stops
        segResizeStop: function (seg, ev) {
            this.isResizingSeg = false;
            this.view.trigger('eventResizeStop', seg.el[0], seg.event, ev, {}); // last argument is jqui dummy
        },
        // Returns new date-information for an event segment being resized from its start
        computeEventStartResize: function (startSpan, endSpan, event) {
            return this.computeEventResize('start', startSpan, endSpan, event);
        },
        // Returns new date-information for an event segment being resized from its end
        computeEventEndResize: function (startSpan, endSpan, event) {
            return this.computeEventResize('end', startSpan, endSpan, event);
        },
        // Returns new zoned date information for an event segment being resized from its start OR end
        // `type` is either 'start' or 'end'.
        // DOES NOT consider overlap/constraint.
        computeEventResize: function (type, startSpan, endSpan, event) {
            var calendar = this.view.calendar;
            var delta = this.diffDates(endSpan[type], startSpan[type]);
            var resizeLocation; // zoned event date properties
            var defaultDuration;

            // build original values to work from, guaranteeing a start and end
            resizeLocation = {
                start: event.start.clone(),
                end: calendar.getEventEnd(event),
                allDay: event.allDay
            };

            // if an all-day event was in a timed area and was resized to a time, adjust start/end to have times
            if (resizeLocation.allDay && durationHasTime(delta)) {
                resizeLocation.allDay = false;
                calendar.normalizeEventTimes(resizeLocation);
            }

            resizeLocation[type].add(delta); // apply delta to start or end

            // if the event was compressed too small, find a new reasonable duration for it
            if (!resizeLocation.start.isBefore(resizeLocation.end)) {

                defaultDuration =
                        this.minResizeDuration || // TODO: hack
                        (event.allDay ?
                                calendar.defaultAllDayEventDuration :
                                calendar.defaultTimedEventDuration);

                if (type == 'start') { // resizing the start?
                    resizeLocation.start = resizeLocation.end.clone().subtract(defaultDuration);
                } else { // resizing the end?
                    resizeLocation.end = resizeLocation.start.clone().add(defaultDuration);
                }
            }

            return resizeLocation;
        },
        // Renders a visual indication of an event being resized.
        // `range` has the updated dates of the event. `seg` is the original segment object involved in the drag.
        // Must return elements used for any mock events.
        renderEventResize: function (range, seg) {
            // subclasses must implement
        },
        // Unrenders a visual indication of an event being resized.
        unrenderEventResize: function () {
            // subclasses must implement
        },
        /* Rendering Utils
         ------------------------------------------------------------------------------------------------------------------*/


        // Compute the text that should be displayed on an event's element.
        // `range` can be the Event object itself, or something range-like, with at least a `start`.
        // If event times are disabled, or the event has no time, will return a blank string.
        // If not specified, formatStr will default to the eventTimeFormat setting,
        // and displayEnd will default to the displayEventEnd setting.
        getEventTimeText: function (range, formatStr, displayEnd) {

            if (formatStr == null) {
                formatStr = this.eventTimeFormat;
            }

            if (displayEnd == null) {
                displayEnd = this.displayEventEnd;
            }

            if (this.displayEventTime && range.start.hasTime()) {
                if (displayEnd && range.end) {
                    return this.view.formatRange(range, formatStr);
                } else {
                    return range.start.format(formatStr);
                }
            }

            return '';
        },
        // Generic utility for generating the HTML classNames for an event segment's element
        getSegClasses: function (seg, isDraggable, isResizable) {
            var view = this.view;
            var event = seg.event;
            var classes = [
                'fc-event',
                seg.isStart ? 'fc-start' : 'fc-not-start',
                seg.isEnd ? 'fc-end' : 'fc-not-end'
            ].concat(
                    event.className,
                    event.source ? event.source.className : []
                    );

            if (isDraggable) {
                classes.push('fc-draggable');
            }
            if (isResizable) {
                classes.push('fc-resizable');
            }

            // event is currently selected? attach a className.
            if (view.isEventSelected(event)) {
                classes.push('fc-selected');
            }

            return classes;
        },
        // Utility for generating event skin-related CSS properties
        getSegSkinCss: function (seg) {
            var event = seg.event;
            var view = this.view;
            var source = event.source || {};
            var eventColor = event.color;
            var sourceColor = source.color;
            var optionColor = view.opt('eventColor');

            return {
                'background-color':
                        event.backgroundColor ||
                        eventColor ||
                        source.backgroundColor ||
                        sourceColor ||
                        view.opt('eventBackgroundColor') ||
                        optionColor,
                'border-color':
                        event.borderColor ||
                        eventColor ||
                        source.borderColor ||
                        sourceColor ||
                        view.opt('eventBorderColor') ||
                        optionColor,
                color:
                        event.textColor ||
                        source.textColor ||
                        view.opt('eventTextColor')
            };
        },
        /* Converting events -> eventRange -> eventSpan -> eventSegs
         ------------------------------------------------------------------------------------------------------------------*/


        // Generates an array of segments for the given single event
        // Can accept an event "location" as well (which only has start/end and no allDay)
        eventToSegs: function (event) {
            return this.eventsToSegs([event]);
        },
        eventToSpan: function (event) {
            return this.eventToSpans(event)[0];
        },
        // Generates spans (always unzoned) for the given event.
        // Does not do any inverting for inverse-background events.
        // Can accept an event "location" as well (which only has start/end and no allDay)
        eventToSpans: function (event) {
            var range = this.eventToRange(event);
            return this.eventRangeToSpans(range, event);
        },
        // Converts an array of event objects into an array of event segment objects.
        // A custom `segSliceFunc` may be given for arbitrarily slicing up events.
        // Doesn't guarantee an order for the resulting array.
        eventsToSegs: function (allEvents, segSliceFunc) {
            var _this = this;
            var eventsById = groupEventsById(allEvents);
            var segs = [];

            $.each(eventsById, function (id, events) {
                var ranges = [];
                var i;

                for (i = 0; i < events.length; i++) {
                    ranges.push(_this.eventToRange(events[i]));
                }

                // inverse-background events (utilize only the first event in calculations)
                if (isInverseBgEvent(events[0])) {
                    ranges = _this.invertRanges(ranges);

                    for (i = 0; i < ranges.length; i++) {
                        segs.push.apply(segs, // append to
                                _this.eventRangeToSegs(ranges[i], events[0], segSliceFunc));
                    }
                }
                // normal event ranges
                else {
                    for (i = 0; i < ranges.length; i++) {
                        segs.push.apply(segs, // append to
                                _this.eventRangeToSegs(ranges[i], events[i], segSliceFunc));
                    }
                }
            });

            return segs;
        },
        // Generates the unzoned start/end dates an event appears to occupy
        // Can accept an event "location" as well (which only has start/end and no allDay)
        eventToRange: function (event) {
            return {
                start: event.start.clone().stripZone(),
                end: (
                        event.end ?
                        event.end.clone() :
                        // derive the end from the start and allDay. compute allDay if necessary
                        this.view.calendar.getDefaultEventEnd(
                                event.allDay != null ?
                                event.allDay :
                                !event.start.hasTime(),
                                event.start
                                )
                        ).stripZone()
            };
        },
        // Given an event's range (unzoned start/end), and the event itself,
        // slice into segments (using the segSliceFunc function if specified)
        eventRangeToSegs: function (range, event, segSliceFunc) {
            var spans = this.eventRangeToSpans(range, event);
            var segs = [];
            var i;

            for (i = 0; i < spans.length; i++) {
                segs.push.apply(segs, // append to
                        this.eventSpanToSegs(spans[i], event, segSliceFunc));
            }

            return segs;
        },
        // Given an event's unzoned date range, return an array of "span" objects.
        // Subclasses can override.
        eventRangeToSpans: function (range, event) {
            return [$.extend({}, range)]; // copy into a single-item array
        },
        // Given an event's span (unzoned start/end and other misc data), and the event itself,
        // slices into segments and attaches event-derived properties to them.
        eventSpanToSegs: function (span, event, segSliceFunc) {
            var segs = segSliceFunc ? segSliceFunc(span) : this.spanToSegs(span);
            var i, seg;

            for (i = 0; i < segs.length; i++) {
                seg = segs[i];
                seg.event = event;
                seg.eventStartMS = +span.start; // TODO: not the best name after making spans unzoned
                seg.eventDurationMS = span.end - span.start;
            }

            return segs;
        },
        // Produces a new array of range objects that will cover all the time NOT covered by the given ranges.
        // SIDE EFFECT: will mutate the given array and will use its date references.
        invertRanges: function (ranges) {
            var view = this.view;
            var viewStart = view.start.clone(); // need a copy
            var viewEnd = view.end.clone(); // need a copy
            var inverseRanges = [];
            var start = viewStart; // the end of the previous range. the start of the new range
            var i, range;

            // ranges need to be in order. required for our date-walking algorithm
            ranges.sort(compareRanges);

            for (i = 0; i < ranges.length; i++) {
                range = ranges[i];

                // add the span of time before the event (if there is any)
                if (range.start > start) { // compare millisecond time (skip any ambig logic)
                    inverseRanges.push({
                        start: start,
                        end: range.start
                    });
                }

                start = range.end;
            }

            // add the span of time after the last event (if there is any)
            if (start < viewEnd) { // compare millisecond time (skip any ambig logic)
                inverseRanges.push({
                    start: start,
                    end: viewEnd
                });
            }

            return inverseRanges;
        },
        sortEventSegs: function (segs) {
            segs.sort(proxy(this, 'compareEventSegs'));
        },
        // A cmp function for determining which segments should take visual priority
        compareEventSegs: function (seg1, seg2) {
            return seg1.eventStartMS - seg2.eventStartMS || // earlier events go first
                    seg2.eventDurationMS - seg1.eventDurationMS || // tie? longer events go first
                    seg2.event.allDay - seg1.event.allDay || // tie? put all-day events first (booleans cast to 0/1)
                    compareByFieldSpecs(seg1.event, seg2.event, this.view.eventOrderSpecs);
        }

    });


    /* Utilities
     ----------------------------------------------------------------------------------------------------------------------*/


    function isBgEvent(event) { // returns true if background OR inverse-background
        var rendering = getEventRendering(event);
        return rendering === 'background' || rendering === 'inverse-background';
    }
    FC.isBgEvent = isBgEvent; // export


    function isInverseBgEvent(event) {
        return getEventRendering(event) === 'inverse-background';
    }


    function getEventRendering(event) {
        return firstDefined((event.source || {}).rendering, event.rendering);
    }


    function groupEventsById(events) {
        var eventsById = {};
        var i, event;

        for (i = 0; i < events.length; i++) {
            event = events[i];
            (eventsById[event._id] || (eventsById[event._id] = [])).push(event);
        }

        return eventsById;
    }


// A cmp function for determining which non-inverted "ranges" (see above) happen earlier
    function compareRanges(range1, range2) {
        return range1.start - range2.start; // earlier ranges go first
    }


    /* External-Dragging-Element Data
     ----------------------------------------------------------------------------------------------------------------------*/

// Require all HTML5 data-* attributes used by FullCalendar to have this prefix.
// A value of '' will query attributes like data-event. A value of 'fc' will query attributes like data-fc-event.
    FC.dataAttrPrefix = '';

// Given a jQuery element that might represent a dragged FullCalendar event, returns an intermediate data structure
// to be used for Event Object creation.
// A defined `.eventProps`, even when empty, indicates that an event should be created.
    function getDraggedElMeta(el) {
        var prefix = FC.dataAttrPrefix;
        var eventProps; // properties for creating the event, not related to date/time
        var startTime; // a Duration
        var duration;
        var stick;

        if (prefix) {
            prefix += '-';
        }
        eventProps = el.data(prefix + 'event') || null;

        if (eventProps) {
            if (typeof eventProps === 'object') {
                eventProps = $.extend({}, eventProps); // make a copy
            } else { // something like 1 or true. still signal event creation
                eventProps = {};
            }

            // pluck special-cased date/time properties
            startTime = eventProps.start;
            if (startTime == null) {
                startTime = eventProps.time;
            } // accept 'time' as well
            duration = eventProps.duration;
            stick = eventProps.stick;
            delete eventProps.start;
            delete eventProps.time;
            delete eventProps.duration;
            delete eventProps.stick;
        }

        // fallback to standalone attribute values for each of the date/time properties
        if (startTime == null) {
            startTime = el.data(prefix + 'start');
        }
        if (startTime == null) {
            startTime = el.data(prefix + 'time');
        } // accept 'time' as well
        if (duration == null) {
            duration = el.data(prefix + 'duration');
        }
        if (stick == null) {
            stick = el.data(prefix + 'stick');
        }

        // massage into correct data types
        startTime = startTime != null ? moment.duration(startTime) : null;
        duration = duration != null ? moment.duration(duration) : null;
        stick = Boolean(stick);

        return {eventProps: eventProps, startTime: startTime, duration: duration, stick: stick};
    }


    ;
    ;

    /*
     A set of rendering and date-related methods for a visual component comprised of one or more rows of day columns.
     Prerequisite: the object being mixed into needs to be a *Grid*
     */
    var DayTableMixin = FC.DayTableMixin = {
        breakOnWeeks: false, // should create a new row for each week?
        dayDates: null, // whole-day dates for each column. left to right
        dayIndices: null, // for each day from start, the offset
        daysPerRow: null,
        rowCnt: null,
        colCnt: null,
        colHeadFormat: null,
        // Populates internal variables used for date calculation and rendering
        updateDayTable: function () {
            var view = this.view;
            var date = this.start.clone();
            var dayIndex = -1;
            var dayIndices = [];
            var dayDates = [];
            var daysPerRow;
            var firstDay;
            var rowCnt;

            while (date.isBefore(this.end)) { // loop each day from start to end
                if (view.isHiddenDay(date)) {
                    dayIndices.push(dayIndex + 0.5); // mark that it's between indices
                } else {
                    dayIndex++;
                    dayIndices.push(dayIndex);
                    dayDates.push(date.clone());
                }
                date.add(1, 'days');
            }

            if (this.breakOnWeeks) {
                // count columns until the day-of-week repeats
                firstDay = dayDates[0].day();
                for (daysPerRow = 1; daysPerRow < dayDates.length; daysPerRow++) {
                    if (dayDates[daysPerRow].day() == firstDay) {
                        break;
                    }
                }
                rowCnt = Math.ceil(dayDates.length / daysPerRow);
            } else {
                rowCnt = 1;
                daysPerRow = dayDates.length;
            }

            this.dayDates = dayDates;
            this.dayIndices = dayIndices;
            this.daysPerRow = daysPerRow;
            this.rowCnt = rowCnt;

            this.updateDayTableCols();
        },
        // Computes and assigned the colCnt property and updates any options that may be computed from it
        updateDayTableCols: function () {
            this.colCnt = this.computeColCnt();
            this.colHeadFormat = this.view.opt('columnFormat') || this.computeColHeadFormat();
        },
        // Determines how many columns there should be in the table
        computeColCnt: function () {
            return this.daysPerRow;
        },
        // Computes the ambiguously-timed moment for the given cell
        getCellDate: function (row, col) {
            return this.dayDates[
                    this.getCellDayIndex(row, col)
            ].clone();
        },
        // Computes the ambiguously-timed date range for the given cell
        getCellRange: function (row, col) {
            var start = this.getCellDate(row, col);
            var end = start.clone().add(1, 'days');

            return {start: start, end: end};
        },
        // Returns the number of day cells, chronologically, from the first of the grid (0-based)
        getCellDayIndex: function (row, col) {
            return row * this.daysPerRow + this.getColDayIndex(col);
        },
        // Returns the numner of day cells, chronologically, from the first cell in *any given row*
        getColDayIndex: function (col) {
            if (this.isRTL) {
                return this.colCnt - 1 - col;
            } else {
                return col;
            }
        },
        // Given a date, returns its chronolocial cell-index from the first cell of the grid.
        // If the date lies between cells (because of hiddenDays), returns a floating-point value between offsets.
        // If before the first offset, returns a negative number.
        // If after the last offset, returns an offset past the last cell offset.
        // Only works for *start* dates of cells. Will not work for exclusive end dates for cells.
        getDateDayIndex: function (date) {
            var dayIndices = this.dayIndices;
            var dayOffset = date.diff(this.start, 'days');

            if (dayOffset < 0) {
                return dayIndices[0] - 1;
            } else if (dayOffset >= dayIndices.length) {
                return dayIndices[dayIndices.length - 1] + 1;
            } else {
                return dayIndices[dayOffset];
            }
        },
        /* Options
         ------------------------------------------------------------------------------------------------------------------*/


        // Computes a default column header formatting string if `colFormat` is not explicitly defined
        computeColHeadFormat: function () {
            // if more than one week row, or if there are a lot of columns with not much space,
            // put just the day numbers will be in each cell
            if (this.rowCnt > 1 || this.colCnt > 10) {
                return 'ddd'; // "Sat"
            }
            // multiple days, so full single date string WON'T be in title text
            else if (this.colCnt > 1) {
                return this.view.opt('dayOfMonthFormat'); // "Sat 12/10"
            }
            // single day, so full single date string will probably be in title text
            else {
                return 'dddd'; // "Saturday"
            }
        },
        /* Slicing
         ------------------------------------------------------------------------------------------------------------------*/


        // Slices up a date range into a segment for every week-row it intersects with
        sliceRangeByRow: function (range) {
            var daysPerRow = this.daysPerRow;
            var normalRange = this.view.computeDayRange(range); // make whole-day range, considering nextDayThreshold
            var rangeFirst = this.getDateDayIndex(normalRange.start); // inclusive first index
            var rangeLast = this.getDateDayIndex(normalRange.end.clone().subtract(1, 'days')); // inclusive last index
            var segs = [];
            var row;
            var rowFirst, rowLast; // inclusive day-index range for current row
            var segFirst, segLast; // inclusive day-index range for segment

            for (row = 0; row < this.rowCnt; row++) {
                rowFirst = row * daysPerRow;
                rowLast = rowFirst + daysPerRow - 1;

                // intersect segment's offset range with the row's
                segFirst = Math.max(rangeFirst, rowFirst);
                segLast = Math.min(rangeLast, rowLast);

                // deal with in-between indices
                segFirst = Math.ceil(segFirst); // in-between starts round to next cell
                segLast = Math.floor(segLast); // in-between ends round to prev cell

                if (segFirst <= segLast) { // was there any intersection with the current row?
                    segs.push({
                        row: row,
                        // normalize to start of row
                        firstRowDayIndex: segFirst - rowFirst,
                        lastRowDayIndex: segLast - rowFirst,
                        // must be matching integers to be the segment's start/end
                        isStart: segFirst === rangeFirst,
                        isEnd: segLast === rangeLast
                    });
                }
            }

            return segs;
        },
        // Slices up a date range into a segment for every day-cell it intersects with.
        // TODO: make more DRY with sliceRangeByRow somehow.
        sliceRangeByDay: function (range) {
            var daysPerRow = this.daysPerRow;
            var normalRange = this.view.computeDayRange(range); // make whole-day range, considering nextDayThreshold
            var rangeFirst = this.getDateDayIndex(normalRange.start); // inclusive first index
            var rangeLast = this.getDateDayIndex(normalRange.end.clone().subtract(1, 'days')); // inclusive last index
            var segs = [];
            var row;
            var rowFirst, rowLast; // inclusive day-index range for current row
            var i;
            var segFirst, segLast; // inclusive day-index range for segment

            for (row = 0; row < this.rowCnt; row++) {
                rowFirst = row * daysPerRow;
                rowLast = rowFirst + daysPerRow - 1;

                for (i = rowFirst; i <= rowLast; i++) {

                    // intersect segment's offset range with the row's
                    segFirst = Math.max(rangeFirst, i);
                    segLast = Math.min(rangeLast, i);

                    // deal with in-between indices
                    segFirst = Math.ceil(segFirst); // in-between starts round to next cell
                    segLast = Math.floor(segLast); // in-between ends round to prev cell

                    if (segFirst <= segLast) { // was there any intersection with the current row?
                        segs.push({
                            row: row,
                            // normalize to start of row
                            firstRowDayIndex: segFirst - rowFirst,
                            lastRowDayIndex: segLast - rowFirst,
                            // must be matching integers to be the segment's start/end
                            isStart: segFirst === rangeFirst,
                            isEnd: segLast === rangeLast
                        });
                    }
                }
            }

            return segs;
        },
        /* Header Rendering
         ------------------------------------------------------------------------------------------------------------------*/


        renderHeadHtml: function () {
            var view = this.view;

            return '' +
                    '<div class="fc-row ' + view.widgetHeaderClass + '">' +
                    '<table>' +
                    '<thead>' +
                    this.renderHeadTrHtml() +
                    '</thead>' +
                    '</table>' +
                    '</div>';
        },
        renderHeadIntroHtml: function () {
            return this.renderIntroHtml(); // fall back to generic
        },
        renderHeadTrHtml: function () {
            return '' +
                    '<tr>' +
                    (this.isRTL ? '' : this.renderHeadIntroHtml()) +
                    this.renderHeadDateCellsHtml() +
                    (this.isRTL ? this.renderHeadIntroHtml() : '') +
                    '</tr>';
        },
        renderHeadDateCellsHtml: function () {
            var htmls = [];
            var col, date;

            for (col = 0; col < this.colCnt; col++) {
                date = this.getCellDate(0, col);
                htmls.push(this.renderHeadDateCellHtml(date));
            }

            return htmls.join('');
        },
        // TODO: when internalApiVersion, accept an object for HTML attributes
        // (colspan should be no different)
        renderHeadDateCellHtml: function (date, colspan, otherAttrs) {
            var view = this.view;

            return '' +
                    '<th class="fc-day-header ' + view.widgetHeaderClass + ' fc-' + dayIDs[date.day()] + '"' +
                    (this.rowCnt == 1 ?
                            ' data-date="' + date.format('YYYY-MM-DD') + '"' :
                            '') +
                    (colspan > 1 ?
                            ' colspan="' + colspan + '"' :
                            '') +
                    (otherAttrs ?
                            ' ' + otherAttrs :
                            '') +
                    '>' +
                    htmlEscape(date.format(this.colHeadFormat)) +
                    '</th>';
        },
        /* Background Rendering
         ------------------------------------------------------------------------------------------------------------------*/


        renderBgTrHtml: function (row) {
            return '' +
                    '<tr>' +
                    (this.isRTL ? '' : this.renderBgIntroHtml(row)) +
                    this.renderBgCellsHtml(row) +
                    (this.isRTL ? this.renderBgIntroHtml(row) : '') +
                    '</tr>';
        },
        renderBgIntroHtml: function (row) {
            return this.renderIntroHtml(); // fall back to generic
        },
        renderBgCellsHtml: function (row) {
            var htmls = [];
            var col, date;

            for (col = 0; col < this.colCnt; col++) {
                date = this.getCellDate(row, col);
                htmls.push(this.renderBgCellHtml(date));
            }

            return htmls.join('');
        },
        renderBgCellHtml: function (date, otherAttrs) {
            var view = this.view;
            var classes = this.getDayClasses(date);

            classes.unshift('fc-day', view.widgetContentClass);

            return '<td class="' + classes.join(' ') + '"' +
                    ' data-date="' + date.format('YYYY-MM-DD') + '"' + // if date has a time, won't format it
                    (otherAttrs ?
                            ' ' + otherAttrs :
                            '') +
                    '></td>';
        },
        /* Generic
         ------------------------------------------------------------------------------------------------------------------*/


        // Generates the default HTML intro for any row. User classes should override
        renderIntroHtml: function () {
        },
        // TODO: a generic method for dealing with <tr>, RTL, intro
        // when increment internalApiVersion
        // wrapTr (scheduler)


        /* Utils
         ------------------------------------------------------------------------------------------------------------------*/


        // Applies the generic "intro" and "outro" HTML to the given cells.
        // Intro means the leftmost cell when the calendar is LTR and the rightmost cell when RTL. Vice-versa for outro.
        bookendCells: function (trEl) {
            var introHtml = this.renderIntroHtml();

            if (introHtml) {
                if (this.isRTL) {
                    trEl.append(introHtml);
                } else {
                    trEl.prepend(introHtml);
                }
            }
        }

    };

    ;
    ;

    /* A component that renders a grid of whole-days that runs horizontally. There can be multiple rows, one per week.
     ----------------------------------------------------------------------------------------------------------------------*/

    var DayGrid = FC.DayGrid = Grid.extend(DayTableMixin, {
        numbersVisible: false, // should render a row for day/week numbers? set by outside view. TODO: make internal
        bottomCoordPadding: 0, // hack for extending the hit area for the last row of the coordinate grid

        rowEls: null, // set of fake row elements
        cellEls: null, // set of whole-day elements comprising the row's background
        helperEls: null, // set of cell skeleton elements for rendering the mock event "helper"

        rowCoordCache: null,
        colCoordCache: null,
        // Renders the rows and columns into the component's `this.el`, which should already be assigned.
        // isRigid determins whether the individual rows should ignore the contents and be a constant height.
        // Relies on the view's colCnt and rowCnt. In the future, this component should probably be self-sufficient.
        renderDates: function (isRigid) {
            var view = this.view;
            var rowCnt = this.rowCnt;
            var colCnt = this.colCnt;
            var html = '';
            var row;
            var col;

            for (row = 0; row < rowCnt; row++) {
                html += this.renderDayRowHtml(row, isRigid);
            }
            this.el.html(html);

            this.rowEls = this.el.find('.fc-row');
            this.cellEls = this.el.find('.fc-day');

            this.rowCoordCache = new CoordCache({
                els: this.rowEls,
                isVertical: true
            });
            this.colCoordCache = new CoordCache({
                els: this.cellEls.slice(0, this.colCnt), // only the first row
                isHorizontal: true
            });

            // trigger dayRender with each cell's element
            for (row = 0; row < rowCnt; row++) {
                for (col = 0; col < colCnt; col++) {
                    view.trigger(
                            'dayRender',
                            null,
                            this.getCellDate(row, col),
                            this.getCellEl(row, col)
                            );
                }
            }
        },
        unrenderDates: function () {
            this.removeSegPopover();
        },
        renderBusinessHours: function () {
            var events = this.view.calendar.getBusinessHoursEvents(true); // wholeDay=true
            var segs = this.eventsToSegs(events);

            this.renderFill('businessHours', segs, 'bgevent');
        },
        // Generates the HTML for a single row, which is a div that wraps a table.
        // `row` is the row number.
        renderDayRowHtml: function (row, isRigid) {
            var view = this.view;
            var classes = ['fc-row', 'fc-week', view.widgetContentClass];

            if (isRigid) {
                classes.push('fc-rigid');
            }

            return '' +
                    '<div class="' + classes.join(' ') + '">' +
                    '<div class="fc-bg">' +
                    '<table>' +
                    this.renderBgTrHtml(row) +
                    '</table>' +
                    '</div>' +
                    '<div class="fc-content-skeleton">' +
                    '<table>' +
                    (this.numbersVisible ?
                            '<thead>' +
                            this.renderNumberTrHtml(row) +
                            '</thead>' :
                            ''
                            ) +
                    '</table>' +
                    '</div>' +
                    '</div>';
        },
        /* Grid Number Rendering
         ------------------------------------------------------------------------------------------------------------------*/


        renderNumberTrHtml: function (row) {
            return '' +
                    '<tr>' +
                    (this.isRTL ? '' : this.renderNumberIntroHtml(row)) +
                    this.renderNumberCellsHtml(row) +
                    (this.isRTL ? this.renderNumberIntroHtml(row) : '') +
                    '</tr>';
        },
        renderNumberIntroHtml: function (row) {
            return this.renderIntroHtml();
        },
        renderNumberCellsHtml: function (row) {
            var htmls = [];
            var col, date;

            for (col = 0; col < this.colCnt; col++) {
                date = this.getCellDate(row, col);
                htmls.push(this.renderNumberCellHtml(date));
            }

            return htmls.join('');
        },
        // Generates the HTML for the <td>s of the "number" row in the DayGrid's content skeleton.
        // The number row will only exist if either day numbers or week numbers are turned on.
        renderNumberCellHtml: function (date) {
            var classes;

            if (!this.view.dayNumbersVisible) { // if there are week numbers but not day numbers
                return '<td/>'; //  will create an empty space above events :(
            }

            classes = this.getDayClasses(date);
            classes.unshift('fc-day-number');

            return '' +
                    '<td class="' + classes.join(' ') + '" data-date="' + date.format() + '">' +
                    date.date() +
                    '</td>';
        },
        /* Options
         ------------------------------------------------------------------------------------------------------------------*/


        // Computes a default event time formatting string if `timeFormat` is not explicitly defined
        computeEventTimeFormat: function () {
            return this.view.opt('extraSmallTimeFormat'); // like "6p" or "6:30p"
        },
        // Computes a default `displayEventEnd` value if one is not expliclty defined
        computeDisplayEventEnd: function () {
            return this.colCnt == 1; // we'll likely have space if there's only one day
        },
        /* Dates
         ------------------------------------------------------------------------------------------------------------------*/


        rangeUpdated: function () {
            this.updateDayTable();
        },
        // Slices up the given span (unzoned start/end with other misc data) into an array of segments
        spanToSegs: function (span) {
            var segs = this.sliceRangeByRow(span);
            var i, seg;

            for (i = 0; i < segs.length; i++) {
                seg = segs[i];
                if (this.isRTL) {
                    seg.leftCol = this.daysPerRow - 1 - seg.lastRowDayIndex;
                    seg.rightCol = this.daysPerRow - 1 - seg.firstRowDayIndex;
                } else {
                    seg.leftCol = seg.firstRowDayIndex;
                    seg.rightCol = seg.lastRowDayIndex;
                }
            }

            return segs;
        },
        /* Hit System
         ------------------------------------------------------------------------------------------------------------------*/


        prepareHits: function () {
            this.colCoordCache.build();
            this.rowCoordCache.build();
            this.rowCoordCache.bottoms[this.rowCnt - 1] += this.bottomCoordPadding; // hack
        },
        releaseHits: function () {
            this.colCoordCache.clear();
            this.rowCoordCache.clear();
        },
        queryHit: function (leftOffset, topOffset) {
            var col = this.colCoordCache.getHorizontalIndex(leftOffset);
            var row = this.rowCoordCache.getVerticalIndex(topOffset);

            if (row != null && col != null) {
                return this.getCellHit(row, col);
            }
        },
        getHitSpan: function (hit) {
            return this.getCellRange(hit.row, hit.col);
        },
        getHitEl: function (hit) {
            return this.getCellEl(hit.row, hit.col);
        },
        /* Cell System
         ------------------------------------------------------------------------------------------------------------------*/
        // FYI: the first column is the leftmost column, regardless of date


        getCellHit: function (row, col) {
            return {
                row: row,
                col: col,
                component: this, // needed unfortunately :(
                left: this.colCoordCache.getLeftOffset(col),
                right: this.colCoordCache.getRightOffset(col),
                top: this.rowCoordCache.getTopOffset(row),
                bottom: this.rowCoordCache.getBottomOffset(row)
            };
        },
        getCellEl: function (row, col) {
            return this.cellEls.eq(row * this.colCnt + col);
        },
        /* Event Drag Visualization
         ------------------------------------------------------------------------------------------------------------------*/
        // TODO: move to DayGrid.event, similar to what we did with Grid's drag methods


        // Renders a visual indication of an event or external element being dragged.
        // `eventLocation` has zoned start and end (optional)
        renderDrag: function (eventLocation, seg) {

            // always render a highlight underneath
            this.renderHighlight(this.eventToSpan(eventLocation));

            // if a segment from the same calendar but another component is being dragged, render a helper event
            if (seg && !seg.el.closest(this.el).length) {

                return this.renderEventLocationHelper(eventLocation, seg); // returns mock event elements
            }
        },
        // Unrenders any visual indication of a hovering event
        unrenderDrag: function () {
            this.unrenderHighlight();
            this.unrenderHelper();
        },
        /* Event Resize Visualization
         ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of an event being resized
        renderEventResize: function (eventLocation, seg) {
            this.renderHighlight(this.eventToSpan(eventLocation));
            return this.renderEventLocationHelper(eventLocation, seg); // returns mock event elements
        },
        // Unrenders a visual indication of an event being resized
        unrenderEventResize: function () {
            this.unrenderHighlight();
            this.unrenderHelper();
        },
        /* Event Helper
         ------------------------------------------------------------------------------------------------------------------*/


        // Renders a mock "helper" event. `sourceSeg` is the associated internal segment object. It can be null.
        renderHelper: function (event, sourceSeg) {
            var helperNodes = [];
            var segs = this.eventToSegs(event);
            var rowStructs;

            segs = this.renderFgSegEls(segs); // assigns each seg's el and returns a subset of segs that were rendered
            rowStructs = this.renderSegRows(segs);

            // inject each new event skeleton into each associated row
            this.rowEls.each(function (row, rowNode) {
                var rowEl = $(rowNode); // the .fc-row
                var skeletonEl = $('<div class="fc-helper-skeleton"><table/></div>'); // will be absolutely positioned
                var skeletonTop;

                // If there is an original segment, match the top position. Otherwise, put it at the row's top level
                if (sourceSeg && sourceSeg.row === row) {
                    skeletonTop = sourceSeg.el.position().top;
                } else {
                    skeletonTop = rowEl.find('.fc-content-skeleton tbody').position().top;
                }

                skeletonEl.css('top', skeletonTop)
                        .find('table')
                        .append(rowStructs[row].tbodyEl);

                rowEl.append(skeletonEl);
                helperNodes.push(skeletonEl[0]);
            });

            return (// must return the elements rendered
                    this.helperEls = $(helperNodes) // array -> jQuery set
                    );
        },
        // Unrenders any visual indication of a mock helper event
        unrenderHelper: function () {
            if (this.helperEls) {
                this.helperEls.remove();
                this.helperEls = null;
            }
        },
        /* Fill System (highlight, background events, business hours)
         ------------------------------------------------------------------------------------------------------------------*/


        fillSegTag: 'td', // override the default tag name


        // Renders a set of rectangles over the given segments of days.
        // Only returns segments that successfully rendered.
        renderFill: function (type, segs, className) {
            var nodes = [];
            var i, seg;
            var skeletonEl;

            segs = this.renderFillSegEls(type, segs); // assignes `.el` to each seg. returns successfully rendered segs

            for (i = 0; i < segs.length; i++) {
                seg = segs[i];
                skeletonEl = this.renderFillRow(type, seg, className);
                this.rowEls.eq(seg.row).append(skeletonEl);
                nodes.push(skeletonEl[0]);
            }

            this.elsByFill[type] = $(nodes);

            return segs;
        },
        // Generates the HTML needed for one row of a fill. Requires the seg's el to be rendered.
        renderFillRow: function (type, seg, className) {
            var colCnt = this.colCnt;
            var startCol = seg.leftCol;
            var endCol = seg.rightCol + 1;
            var skeletonEl;
            var trEl;

            className = className || type.toLowerCase();

            skeletonEl = $(
                    '<div class="fc-' + className + '-skeleton">' +
                    '<table><tr/></table>' +
                    '</div>'
                    );
            trEl = skeletonEl.find('tr');

            if (startCol > 0) {
                trEl.append('<td colspan="' + startCol + '"/>');
            }

            trEl.append(
                    seg.el.attr('colspan', endCol - startCol)
                    );

            if (endCol < colCnt) {
                trEl.append('<td colspan="' + (colCnt - endCol) + '"/>');
            }

            this.bookendCells(trEl);

            return skeletonEl;
        }

    });

    ;
    ;

    /* Event-rendering methods for the DayGrid class
     ----------------------------------------------------------------------------------------------------------------------*/

    DayGrid.mixin({
        rowStructs: null, // an array of objects, each holding information about a row's foreground event-rendering


        // Unrenders all events currently rendered on the grid
        unrenderEvents: function () {
            this.removeSegPopover(); // removes the "more.." events popover
            Grid.prototype.unrenderEvents.apply(this, arguments); // calls the super-method
        },
        // Retrieves all rendered segment objects currently rendered on the grid
        getEventSegs: function () {
            return Grid.prototype.getEventSegs.call(this) // get the segments from the super-method
                    .concat(this.popoverSegs || []); // append the segments from the "more..." popover
        },
        // Renders the given background event segments onto the grid
        renderBgSegs: function (segs) {

            // don't render timed background events
            var allDaySegs = $.grep(segs, function (seg) {
                return seg.event.allDay;
            });

            return Grid.prototype.renderBgSegs.call(this, allDaySegs); // call the super-method
        },
        // Renders the given foreground event segments onto the grid
        renderFgSegs: function (segs) {
            var rowStructs;

            // render an `.el` on each seg
            // returns a subset of the segs. segs that were actually rendered
            segs = this.renderFgSegEls(segs);

            rowStructs = this.rowStructs = this.renderSegRows(segs);

            // append to each row's content skeleton
            this.rowEls.each(function (i, rowNode) {
                $(rowNode).find('.fc-content-skeleton > table').append(
                        rowStructs[i].tbodyEl
                        );
            });

            return segs; // return only the segs that were actually rendered
        },
        // Unrenders all currently rendered foreground event segments
        unrenderFgSegs: function () {
            var rowStructs = this.rowStructs || [];
            var rowStruct;

            while ((rowStruct = rowStructs.pop())) {
                rowStruct.tbodyEl.remove();
            }

            this.rowStructs = null;
        },
        // Uses the given events array to generate <tbody> elements that should be appended to each row's content skeleton.
        // Returns an array of rowStruct objects (see the bottom of `renderSegRow`).
        // PRECONDITION: each segment shoud already have a rendered and assigned `.el`
        renderSegRows: function (segs) {
            var rowStructs = [];
            var segRows;
            var row;

            segRows = this.groupSegRows(segs); // group into nested arrays

            // iterate each row of segment groupings
            for (row = 0; row < segRows.length; row++) {
                rowStructs.push(
                        this.renderSegRow(row, segRows[row])
                        );
            }

            return rowStructs;
        },
        // Builds the HTML to be used for the default element for an individual segment
        fgSegHtml: function (seg, disableResizing) {
            var view = this.view;
            var event = seg.event;
            var isDraggable = view.isEventDraggable(event);
            var isResizableFromStart = !disableResizing && event.allDay &&
                    seg.isStart && view.isEventResizableFromStart(event);
            var isResizableFromEnd = !disableResizing && event.allDay &&
                    seg.isEnd && view.isEventResizableFromEnd(event);
            var classes = this.getSegClasses(seg, isDraggable, isResizableFromStart || isResizableFromEnd);
            var skinCss = cssToStr(this.getSegSkinCss(seg));
            var timeHtml = '';
            var timeText;
            var titleHtml;

            classes.unshift('fc-day-grid-event', 'fc-h-event');

            // Only display a timed events time if it is the starting segment
            if (seg.isStart) {
                timeText = this.getEventTimeText(event);
                if (timeText) {
                    timeHtml = '<span class="fc-time">' + htmlEscape(timeText) + '</span>';
                }
            }

            titleHtml =
                    '<span class="fc-title">' +
                    (htmlEscape(event.title || '') || '&nbsp;') + // we always want one line of height
                    '</span>';

            return '<a class="' + classes.join(' ') + '"' +
                    (event.url ?
                            ' href="' + htmlEscape(event.url) + '"' :
                            ''
                            ) +
                    (skinCss ?
                            ' style="' + skinCss + '"' :
                            ''
                            ) +
                    '>' +
                    '<div class="fc-content">' +
                    (this.isRTL ?
                            titleHtml + ' ' + timeHtml : // put a natural space in between
                            timeHtml + ' ' + titleHtml   //
                            ) +
                    '</div>' +
                    (isResizableFromStart ?
                            '<div class="fc-resizer fc-start-resizer" />' :
                            ''
                            ) +
                    (isResizableFromEnd ?
                            '<div class="fc-resizer fc-end-resizer" />' :
                            ''
                            ) +
                    '</a>';
        },
        // Given a row # and an array of segments all in the same row, render a <tbody> element, a skeleton that contains
        // the segments. Returns object with a bunch of internal data about how the render was calculated.
        // NOTE: modifies rowSegs
        renderSegRow: function (row, rowSegs) {
            var colCnt = this.colCnt;
            var segLevels = this.buildSegLevels(rowSegs); // group into sub-arrays of levels
            var levelCnt = Math.max(1, segLevels.length); // ensure at least one level
            var tbody = $('<tbody/>');
            var segMatrix = []; // lookup for which segments are rendered into which level+col cells
            var cellMatrix = []; // lookup for all <td> elements of the level+col matrix
            var loneCellMatrix = []; // lookup for <td> elements that only take up a single column
            var i, levelSegs;
            var col;
            var tr;
            var j, seg;
            var td;

            // populates empty cells from the current column (`col`) to `endCol`
            function emptyCellsUntil(endCol) {
                while (col < endCol) {
                    // try to grab a cell from the level above and extend its rowspan. otherwise, create a fresh cell
                    td = (loneCellMatrix[i - 1] || [])[col];
                    if (td) {
                        td.attr(
                                'rowspan',
                                parseInt(td.attr('rowspan') || 1, 10) + 1
                                );
                    } else {
                        td = $('<td/>');
                        tr.append(td);
                    }
                    cellMatrix[i][col] = td;
                    loneCellMatrix[i][col] = td;
                    col++;
                }
            }

            for (i = 0; i < levelCnt; i++) { // iterate through all levels
                levelSegs = segLevels[i];
                col = 0;
                tr = $('<tr/>');

                segMatrix.push([]);
                cellMatrix.push([]);
                loneCellMatrix.push([]);

                // levelCnt might be 1 even though there are no actual levels. protect against this.
                // this single empty row is useful for styling.
                if (levelSegs) {
                    for (j = 0; j < levelSegs.length; j++) { // iterate through segments in level
                        seg = levelSegs[j];

                        emptyCellsUntil(seg.leftCol);

                        // create a container that occupies or more columns. append the event element.
                        td = $('<td class="fc-event-container"/>').append(seg.el);
                        if (seg.leftCol != seg.rightCol) {
                            td.attr('colspan', seg.rightCol - seg.leftCol + 1);
                        } else { // a single-column segment
                            loneCellMatrix[i][col] = td;
                        }

                        while (col <= seg.rightCol) {
                            cellMatrix[i][col] = td;
                            segMatrix[i][col] = seg;
                            col++;
                        }

                        tr.append(td);
                    }
                }

                emptyCellsUntil(colCnt); // finish off the row
                this.bookendCells(tr);
                tbody.append(tr);
            }

            return {// a "rowStruct"
                row: row, // the row number
                tbodyEl: tbody,
                cellMatrix: cellMatrix,
                segMatrix: segMatrix,
                segLevels: segLevels,
                segs: rowSegs
            };
        },
        // Stacks a flat array of segments, which are all assumed to be in the same row, into subarrays of vertical levels.
        // NOTE: modifies segs
        buildSegLevels: function (segs) {
            var levels = [];
            var i, seg;
            var j;

            // Give preference to elements with certain criteria, so they have
            // a chance to be closer to the top.
            this.sortEventSegs(segs);

            for (i = 0; i < segs.length; i++) {
                seg = segs[i];

                // loop through levels, starting with the topmost, until the segment doesn't collide with other segments
                for (j = 0; j < levels.length; j++) {
                    if (!isDaySegCollision(seg, levels[j])) {
                        break;
                    }
                }
                // `j` now holds the desired subrow index
                seg.level = j;

                // create new level array if needed and append segment
                (levels[j] || (levels[j] = [])).push(seg);
            }

            // order segments left-to-right. very important if calendar is RTL
            for (j = 0; j < levels.length; j++) {
                levels[j].sort(compareDaySegCols);
            }

            return levels;
        },
        // Given a flat array of segments, return an array of sub-arrays, grouped by each segment's row
        groupSegRows: function (segs) {
            var segRows = [];
            var i;

            for (i = 0; i < this.rowCnt; i++) {
                segRows.push([]);
            }

            for (i = 0; i < segs.length; i++) {
                segRows[segs[i].row].push(segs[i]);
            }

            return segRows;
        }

    });


// Computes whether two segments' columns collide. They are assumed to be in the same row.
    function isDaySegCollision(seg, otherSegs) {
        var i, otherSeg;

        for (i = 0; i < otherSegs.length; i++) {
            otherSeg = otherSegs[i];

            if (
                    otherSeg.leftCol <= seg.rightCol &&
                    otherSeg.rightCol >= seg.leftCol
                    ) {
                return true;
            }
        }

        return false;
    }


// A cmp function for determining the leftmost event
    function compareDaySegCols(a, b) {
        return a.leftCol - b.leftCol;
    }

    ;
    ;

    /* Methods relate to limiting the number events for a given day on a DayGrid
     ----------------------------------------------------------------------------------------------------------------------*/
// NOTE: all the segs being passed around in here are foreground segs

    DayGrid.mixin({
        segPopover: null, // the Popover that holds events that can't fit in a cell. null when not visible
        popoverSegs: null, // an array of segment objects that the segPopover holds. null when not visible


        removeSegPopover: function () {
            if (this.segPopover) {
                this.segPopover.hide(); // in handler, will call segPopover's removeElement
            }
        },
        // Limits the number of "levels" (vertically stacking layers of events) for each row of the grid.
        // `levelLimit` can be false (don't limit), a number, or true (should be computed).
        limitRows: function (levelLimit) {
            var rowStructs = this.rowStructs || [];
            var row; // row #
            var rowLevelLimit;

            for (row = 0; row < rowStructs.length; row++) {
                this.unlimitRow(row);

                if (!levelLimit) {
                    rowLevelLimit = false;
                } else if (typeof levelLimit === 'number') {
                    rowLevelLimit = levelLimit;
                } else {
                    rowLevelLimit = this.computeRowLevelLimit(row);
                }

                if (rowLevelLimit !== false) {
                    this.limitRow(row, rowLevelLimit);
                }
            }
        },
        // Computes the number of levels a row will accomodate without going outside its bounds.
        // Assumes the row is "rigid" (maintains a constant height regardless of what is inside).
        // `row` is the row number.
        computeRowLevelLimit: function (row) {
            var rowEl = this.rowEls.eq(row); // the containing "fake" row div
            var rowHeight = rowEl.height(); // TODO: cache somehow?
            var trEls = this.rowStructs[row].tbodyEl.children();
            var i, trEl;
            var trHeight;

            function iterInnerHeights(i, childNode) {
                trHeight = Math.max(trHeight, $(childNode).outerHeight());
            }

            // Reveal one level <tr> at a time and stop when we find one out of bounds
            for (i = 0; i < trEls.length; i++) {
                trEl = trEls.eq(i).removeClass('fc-limited'); // reset to original state (reveal)

                // with rowspans>1 and IE8, trEl.outerHeight() would return the height of the largest cell,
                // so instead, find the tallest inner content element.
                trHeight = 0;
                trEl.find('> td > :first-child').each(iterInnerHeights);

                if (trEl.position().top + trHeight > rowHeight) {
                    return i;
                }
            }

            return false; // should not limit at all
        },
        // Limits the given grid row to the maximum number of levels and injects "more" links if necessary.
        // `row` is the row number.
        // `levelLimit` is a number for the maximum (inclusive) number of levels allowed.
        limitRow: function (row, levelLimit) {
            var _this = this;
            var rowStruct = this.rowStructs[row];
            var moreNodes = []; // array of "more" <a> links and <td> DOM nodes
            var col = 0; // col #, left-to-right (not chronologically)
            var levelSegs; // array of segment objects in the last allowable level, ordered left-to-right
            var cellMatrix; // a matrix (by level, then column) of all <td> jQuery elements in the row
            var limitedNodes; // array of temporarily hidden level <tr> and segment <td> DOM nodes
            var i, seg;
            var segsBelow; // array of segment objects below `seg` in the current `col`
            var totalSegsBelow; // total number of segments below `seg` in any of the columns `seg` occupies
            var colSegsBelow; // array of segment arrays, below seg, one for each column (offset from segs's first column)
            var td, rowspan;
            var segMoreNodes; // array of "more" <td> cells that will stand-in for the current seg's cell
            var j;
            var moreTd, moreWrap, moreLink;

            // Iterates through empty level cells and places "more" links inside if need be
            function emptyCellsUntil(endCol) { // goes from current `col` to `endCol`
                while (col < endCol) {
                    segsBelow = _this.getCellSegs(row, col, levelLimit);
                    if (segsBelow.length) {
                        td = cellMatrix[levelLimit - 1][col];
                        moreLink = _this.renderMoreLink(row, col, segsBelow);
                        moreWrap = $('<div/>').append(moreLink);
                        td.append(moreWrap);
                        moreNodes.push(moreWrap[0]);
                    }
                    col++;
                }
            }

            if (levelLimit && levelLimit < rowStruct.segLevels.length) { // is it actually over the limit?
                levelSegs = rowStruct.segLevels[levelLimit - 1];
                cellMatrix = rowStruct.cellMatrix;

                limitedNodes = rowStruct.tbodyEl.children().slice(levelLimit) // get level <tr> elements past the limit
                        .addClass('fc-limited').get(); // hide elements and get a simple DOM-nodes array

                // iterate though segments in the last allowable level
                for (i = 0; i < levelSegs.length; i++) {
                    seg = levelSegs[i];
                    emptyCellsUntil(seg.leftCol); // process empty cells before the segment

                    // determine *all* segments below `seg` that occupy the same columns
                    colSegsBelow = [];
                    totalSegsBelow = 0;
                    while (col <= seg.rightCol) {
                        segsBelow = this.getCellSegs(row, col, levelLimit);
                        colSegsBelow.push(segsBelow);
                        totalSegsBelow += segsBelow.length;
                        col++;
                    }

                    if (totalSegsBelow) { // do we need to replace this segment with one or many "more" links?
                        td = cellMatrix[levelLimit - 1][seg.leftCol]; // the segment's parent cell
                        rowspan = td.attr('rowspan') || 1;
                        segMoreNodes = [];

                        // make a replacement <td> for each column the segment occupies. will be one for each colspan
                        for (j = 0; j < colSegsBelow.length; j++) {
                            moreTd = $('<td class="fc-more-cell"/>').attr('rowspan', rowspan);
                            segsBelow = colSegsBelow[j];
                            moreLink = this.renderMoreLink(
                                    row,
                                    seg.leftCol + j,
                                    [seg].concat(segsBelow) // count seg as hidden too
                                    );
                            moreWrap = $('<div/>').append(moreLink);
                            moreTd.append(moreWrap);
                            segMoreNodes.push(moreTd[0]);
                            moreNodes.push(moreTd[0]);
                        }

                        td.addClass('fc-limited').after($(segMoreNodes)); // hide original <td> and inject replacements
                        limitedNodes.push(td[0]);
                    }
                }

                emptyCellsUntil(this.colCnt); // finish off the level
                rowStruct.moreEls = $(moreNodes); // for easy undoing later
                rowStruct.limitedEls = $(limitedNodes); // for easy undoing later
            }
        },
        // Reveals all levels and removes all "more"-related elements for a grid's row.
        // `row` is a row number.
        unlimitRow: function (row) {
            var rowStruct = this.rowStructs[row];

            if (rowStruct.moreEls) {
                rowStruct.moreEls.remove();
                rowStruct.moreEls = null;
            }

            if (rowStruct.limitedEls) {
                rowStruct.limitedEls.removeClass('fc-limited');
                rowStruct.limitedEls = null;
            }
        },
        // Renders an <a> element that represents hidden event element for a cell.
        // Responsible for attaching click handler as well.
        renderMoreLink: function (row, col, hiddenSegs) {
            var _this = this;
            var view = this.view;

            return $('<a class="fc-more"/>')
                    .text(
                            this.getMoreLinkText(hiddenSegs.length)
                            )
                    .on('click', function (ev) {
                        var clickOption = view.opt('eventLimitClick');
                        var date = _this.getCellDate(row, col);
                        var moreEl = $(this);
                        var dayEl = _this.getCellEl(row, col);
                        var allSegs = _this.getCellSegs(row, col);

                        // rescope the segments to be within the cell's date
                        var reslicedAllSegs = _this.resliceDaySegs(allSegs, date);
                        var reslicedHiddenSegs = _this.resliceDaySegs(hiddenSegs, date);

                        if (typeof clickOption === 'function') {
                            // the returned value can be an atomic option
                            clickOption = view.trigger('eventLimitClick', null, {
                                date: date,
                                dayEl: dayEl,
                                moreEl: moreEl,
                                segs: reslicedAllSegs,
                                hiddenSegs: reslicedHiddenSegs
                            }, ev);
                        }

                        if (clickOption === 'popover') {
                            _this.showSegPopover(row, col, moreEl, reslicedAllSegs);
                        } else if (typeof clickOption === 'string') { // a view name
                            view.calendar.zoomTo(date, clickOption);
                        }
                    });
        },
        // Reveals the popover that displays all events within a cell
        showSegPopover: function (row, col, moreLink, segs) {
            var _this = this;
            var view = this.view;
            var moreWrap = moreLink.parent(); // the <div> wrapper around the <a>
            var topEl; // the element we want to match the top coordinate of
            var options;

            if (this.rowCnt == 1) {
                topEl = view.el; // will cause the popover to cover any sort of header
            } else {
                topEl = this.rowEls.eq(row); // will align with top of row
            }

            options = {
                className: 'fc-more-popover',
                content: this.renderSegPopoverContent(row, col, segs),
                parentEl: this.el,
                top: topEl.offset().top,
                autoHide: true, // when the user clicks elsewhere, hide the popover
                viewportConstrain: view.opt('popoverViewportConstrain'),
                hide: function () {
                    // kill everything when the popover is hidden
                    _this.segPopover.removeElement();
                    _this.segPopover = null;
                    _this.popoverSegs = null;
                }
            };

            // Determine horizontal coordinate.
            // We use the moreWrap instead of the <td> to avoid border confusion.
            if (this.isRTL) {
                options.right = moreWrap.offset().left + moreWrap.outerWidth() + 1; // +1 to be over cell border
            } else {
                options.left = moreWrap.offset().left - 1; // -1 to be over cell border
            }

            this.segPopover = new Popover(options);
            this.segPopover.show();
        },
        // Builds the inner DOM contents of the segment popover
        renderSegPopoverContent: function (row, col, segs) {
            var view = this.view;
            var isTheme = view.opt('theme');
            var title = this.getCellDate(row, col).format(view.opt('dayPopoverFormat'));
            var content = $(
                    '<div class="fc-header ' + view.widgetHeaderClass + '">' +
                    '<span class="fc-close ' +
                    (isTheme ? 'ui-icon ui-icon-closethick' : 'fc-icon fc-icon-x') +
                    '"></span>' +
                    '<span class="fc-title">' +
                    htmlEscape(title) +
                    '</span>' +
                    '<div class="fc-clear"/>' +
                    '</div>' +
                    '<div class="fc-body ' + view.widgetContentClass + '">' +
                    '<div class="fc-event-container"></div>' +
                    '</div>'
                    );
            var segContainer = content.find('.fc-event-container');
            var i;

            // render each seg's `el` and only return the visible segs
            segs = this.renderFgSegEls(segs, true); // disableResizing=true
            this.popoverSegs = segs;

            for (i = 0; i < segs.length; i++) {

                // because segments in the popover are not part of a grid coordinate system, provide a hint to any
                // grids that want to do drag-n-drop about which cell it came from
                this.prepareHits();
                segs[i].hit = this.getCellHit(row, col);
                this.releaseHits();

                segContainer.append(segs[i].el);
            }

            return content;
        },
        // Given the events within an array of segment objects, reslice them to be in a single day
        resliceDaySegs: function (segs, dayDate) {

            // build an array of the original events
            var events = $.map(segs, function (seg) {
                return seg.event;
            });

            var dayStart = dayDate.clone();
            var dayEnd = dayStart.clone().add(1, 'days');
            var dayRange = {start: dayStart, end: dayEnd};

            // slice the events with a custom slicing function
            segs = this.eventsToSegs(
                    events,
                    function (range) {
                        var seg = intersectRanges(range, dayRange); // undefind if no intersection
                        return seg ? [seg] : []; // must return an array of segments
                    }
            );

            // force an order because eventsToSegs doesn't guarantee one
            this.sortEventSegs(segs);

            return segs;
        },
        // Generates the text that should be inside a "more" link, given the number of events it represents
        getMoreLinkText: function (num) {
            var opt = this.view.opt('eventLimitText');

            if (typeof opt === 'function') {
                return opt(num);
            } else {
                return '+' + num + ' ' + opt;
            }
        },
        // Returns segments within a given cell.
        // If `startLevel` is specified, returns only events including and below that level. Otherwise returns all segs.
        getCellSegs: function (row, col, startLevel) {
            var segMatrix = this.rowStructs[row].segMatrix;
            var level = startLevel || 0;
            var segs = [];
            var seg;

            while (level < segMatrix.length) {
                seg = segMatrix[level][col];
                if (seg) {
                    segs.push(seg);
                }
                level++;
            }

            return segs;
        }

    });

    ;
    ;

    /* A component that renders one or more columns of vertical time slots
     ----------------------------------------------------------------------------------------------------------------------*/
// We mixin DayTable, even though there is only a single row of days

    var TimeGrid = FC.TimeGrid = Grid.extend(DayTableMixin, {
        slotDuration: null, // duration of a "slot", a distinct time segment on given day, visualized by lines
        snapDuration: null, // granularity of time for dragging and selecting
        snapsPerSlot: null,
        minTime: null, // Duration object that denotes the first visible time of any given day
        maxTime: null, // Duration object that denotes the exclusive visible end time of any given day
        labelFormat: null, // formatting string for times running along vertical axis
        labelInterval: null, // duration of how often a label should be displayed for a slot

        colEls: null, // cells elements in the day-row background
        slatContainerEl: null, // div that wraps all the slat rows
        slatEls: null, // elements running horizontally across all columns
        nowIndicatorEls: null,
        colCoordCache: null,
        slatCoordCache: null,
        constructor: function () {
            Grid.apply(this, arguments); // call the super-constructor

            this.processOptions();
        },
        // Renders the time grid into `this.el`, which should already be assigned.
        // Relies on the view's colCnt. In the future, this component should probably be self-sufficient.
        renderDates: function () {
            this.el.html(this.renderHtml());
            this.colEls = this.el.find('.fc-day');
            this.slatContainerEl = this.el.find('.fc-slats');
            this.slatEls = this.slatContainerEl.find('tr');

            this.colCoordCache = new CoordCache({
                els: this.colEls,
                isHorizontal: true
            });
            this.slatCoordCache = new CoordCache({
                els: this.slatEls,
                isVertical: true
            });

            this.renderContentSkeleton();
        },
        // Renders the basic HTML skeleton for the grid
        renderHtml: function () {
            return '' +
                    '<div class="fc-bg">' +
                    '<table>' +
                    this.renderBgTrHtml(0) + // row=0
                    '</table>' +
                    '</div>' +
                    '<div class="fc-slats">' +
                    '<table>' +
                    this.renderSlatRowHtml() +
                    '</table>' +
                    '</div>';
        },
        // Generates the HTML for the horizontal "slats" that run width-wise. Has a time axis on a side. Depends on RTL.
        renderSlatRowHtml: function () {
            var view = this.view;
            var isRTL = this.isRTL;
            var html = '';
            var slotTime = moment.duration(+this.minTime); // wish there was .clone() for durations
            var slotDate; // will be on the view's first day, but we only care about its time
            var isLabeled;
            var axisHtml;

            // Calculate the time for each slot
            while (slotTime < this.maxTime) {
                slotDate = this.start.clone().time(slotTime);
                isLabeled = isInt(divideDurationByDuration(slotTime, this.labelInterval));

                axisHtml =
                        '<td class="fc-axis fc-time ' + view.widgetContentClass + '" ' + view.axisStyleAttr() + '>' +
                        (isLabeled ?
                                '<span>' + // for matchCellWidths
                                htmlEscape(slotDate.format(this.labelFormat)) +
                                '</span>' :
                                ''
                                ) +
                        '</td>';

                html +=
                        '<tr data-time="' + slotDate.format('HH:mm:ss') + '"' +
                        (isLabeled ? '' : ' class="fc-minor"') +
                        '>' +
                        (!isRTL ? axisHtml : '') +
                        '<td class="' + view.widgetContentClass + '"/>' +
                        (isRTL ? axisHtml : '') +
                        "</tr>";

                slotTime.add(this.slotDuration);
            }

            return html;
        },
        /* Options
         ------------------------------------------------------------------------------------------------------------------*/


        // Parses various options into properties of this object
        processOptions: function () {
            var view = this.view;
            var slotDuration = view.opt('slotDuration');
            var snapDuration = view.opt('snapDuration');
            var input;

            slotDuration = moment.duration(slotDuration);
            snapDuration = snapDuration ? moment.duration(snapDuration) : slotDuration;

            this.slotDuration = slotDuration;
            this.snapDuration = snapDuration;
            this.snapsPerSlot = slotDuration / snapDuration; // TODO: ensure an integer multiple?

            this.minResizeDuration = snapDuration; // hack

            this.minTime = moment.duration(view.opt('minTime'));
            this.maxTime = moment.duration(view.opt('maxTime'));

            // might be an array value (for TimelineView).
            // if so, getting the most granular entry (the last one probably).
            input = view.opt('slotLabelFormat');
            if ($.isArray(input)) {
                input = input[input.length - 1];
            }

            this.labelFormat =
                    input ||
                    view.opt('axisFormat') || // deprecated
                    view.opt('smallTimeFormat'); // the computed default

            input = view.opt('slotLabelInterval');
            this.labelInterval = input ?
                    moment.duration(input) :
                    this.computeLabelInterval(slotDuration);
        },
        // Computes an automatic value for slotLabelInterval
        computeLabelInterval: function (slotDuration) {
            var i;
            var labelInterval;
            var slotsPerLabel;

            // find the smallest stock label interval that results in more than one slots-per-label
            for (i = AGENDA_STOCK_SUB_DURATIONS.length - 1; i >= 0; i--) {
                labelInterval = moment.duration(AGENDA_STOCK_SUB_DURATIONS[i]);
                slotsPerLabel = divideDurationByDuration(labelInterval, slotDuration);
                if (isInt(slotsPerLabel) && slotsPerLabel > 1) {
                    return labelInterval;
                }
            }

            return moment.duration(slotDuration); // fall back. clone
        },
        // Computes a default event time formatting string if `timeFormat` is not explicitly defined
        computeEventTimeFormat: function () {
            return this.view.opt('noMeridiemTimeFormat'); // like "6:30" (no AM/PM)
        },
        // Computes a default `displayEventEnd` value if one is not expliclty defined
        computeDisplayEventEnd: function () {
            return true;
        },
        /* Hit System
         ------------------------------------------------------------------------------------------------------------------*/


        prepareHits: function () {
            this.colCoordCache.build();
            this.slatCoordCache.build();
        },
        releaseHits: function () {
            this.colCoordCache.clear();
            // NOTE: don't clear slatCoordCache because we rely on it for computeTimeTop
        },
        queryHit: function (leftOffset, topOffset) {
            var snapsPerSlot = this.snapsPerSlot;
            var colCoordCache = this.colCoordCache;
            var slatCoordCache = this.slatCoordCache;
            var colIndex = colCoordCache.getHorizontalIndex(leftOffset);
            var slatIndex = slatCoordCache.getVerticalIndex(topOffset);

            if (colIndex != null && slatIndex != null) {
                var slatTop = slatCoordCache.getTopOffset(slatIndex);
                var slatHeight = slatCoordCache.getHeight(slatIndex);
                var partial = (topOffset - slatTop) / slatHeight; // floating point number between 0 and 1
                var localSnapIndex = Math.floor(partial * snapsPerSlot); // the snap # relative to start of slat
                var snapIndex = slatIndex * snapsPerSlot + localSnapIndex;
                var snapTop = slatTop + (localSnapIndex / snapsPerSlot) * slatHeight;
                var snapBottom = slatTop + ((localSnapIndex + 1) / snapsPerSlot) * slatHeight;

                return {
                    col: colIndex,
                    snap: snapIndex,
                    component: this, // needed unfortunately :(
                    left: colCoordCache.getLeftOffset(colIndex),
                    right: colCoordCache.getRightOffset(colIndex),
                    top: snapTop,
                    bottom: snapBottom
                };
            }
        },
        getHitSpan: function (hit) {
            var start = this.getCellDate(0, hit.col); // row=0
            var time = this.computeSnapTime(hit.snap); // pass in the snap-index
            var end;

            start.time(time);
            end = start.clone().add(this.snapDuration);

            return {start: start, end: end};
        },
        getHitEl: function (hit) {
            return this.colEls.eq(hit.col);
        },
        /* Dates
         ------------------------------------------------------------------------------------------------------------------*/


        rangeUpdated: function () {
            this.updateDayTable();
        },
        // Given a row number of the grid, representing a "snap", returns a time (Duration) from its start-of-day
        computeSnapTime: function (snapIndex) {
            return moment.duration(this.minTime + this.snapDuration * snapIndex);
        },
        // Slices up the given span (unzoned start/end with other misc data) into an array of segments
        spanToSegs: function (span) {
            var segs = this.sliceRangeByTimes(span);
            var i;

            for (i = 0; i < segs.length; i++) {
                if (this.isRTL) {
                    segs[i].col = this.daysPerRow - 1 - segs[i].dayIndex;
                } else {
                    segs[i].col = segs[i].dayIndex;
                }
            }

            return segs;
        },
        sliceRangeByTimes: function (range) {
            var segs = [];
            var seg;
            var dayIndex;
            var dayDate;
            var dayRange;

            for (dayIndex = 0; dayIndex < this.daysPerRow; dayIndex++) {
                dayDate = this.dayDates[dayIndex].clone(); // TODO: better API for this?
                dayRange = {
                    start: dayDate.clone().time(this.minTime),
                    end: dayDate.clone().time(this.maxTime)
                };
                seg = intersectRanges(range, dayRange); // both will be ambig timezone
                if (seg) {
                    seg.dayIndex = dayIndex;
                    segs.push(seg);
                }
            }

            return segs;
        },
        /* Coordinates
         ------------------------------------------------------------------------------------------------------------------*/


        updateSize: function (isResize) { // NOT a standard Grid method
            this.slatCoordCache.build();

            if (isResize) {
                this.updateSegVerticals(
                        [].concat(this.fgSegs || [], this.bgSegs || [], this.businessSegs || [])
                        );
            }
        },
        getTotalSlatHeight: function () {
            return this.slatContainerEl.outerHeight();
        },
        // Computes the top coordinate, relative to the bounds of the grid, of the given date.
        // A `startOfDayDate` must be given for avoiding ambiguity over how to treat midnight.
        computeDateTop: function (date, startOfDayDate) {
            return this.computeTimeTop(
                    moment.duration(
                            date - startOfDayDate.clone().stripTime()
                            )
                    );
        },
        // Computes the top coordinate, relative to the bounds of the grid, of the given time (a Duration).
        computeTimeTop: function (time) {
            var len = this.slatEls.length;
            var slatCoverage = (time - this.minTime) / this.slotDuration; // floating-point value of # of slots covered
            var slatIndex;
            var slatRemainder;

            // compute a floating-point number for how many slats should be progressed through.
            // from 0 to number of slats (inclusive)
            // constrained because minTime/maxTime might be customized.
            slatCoverage = Math.max(0, slatCoverage);
            slatCoverage = Math.min(len, slatCoverage);

            // an integer index of the furthest whole slat
            // from 0 to number slats (*exclusive*, so len-1)
            slatIndex = Math.floor(slatCoverage);
            slatIndex = Math.min(slatIndex, len - 1);

            // how much further through the slatIndex slat (from 0.0-1.0) must be covered in addition.
            // could be 1.0 if slatCoverage is covering *all* the slots
            slatRemainder = slatCoverage - slatIndex;

            return this.slatCoordCache.getTopPosition(slatIndex) +
                    this.slatCoordCache.getHeight(slatIndex) * slatRemainder;
        },
        /* Event Drag Visualization
         ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of an event being dragged over the specified date(s).
        // A returned value of `true` signals that a mock "helper" event has been rendered.
        renderDrag: function (eventLocation, seg) {

            if (seg) { // if there is event information for this drag, render a helper event

                // returns mock event elements
                // signal that a helper has been rendered
                return this.renderEventLocationHelper(eventLocation, seg);
            } else {
                // otherwise, just render a highlight
                this.renderHighlight(this.eventToSpan(eventLocation));
            }
        },
        // Unrenders any visual indication of an event being dragged
        unrenderDrag: function () {
            this.unrenderHelper();
            this.unrenderHighlight();
        },
        /* Event Resize Visualization
         ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of an event being resized
        renderEventResize: function (eventLocation, seg) {
            return this.renderEventLocationHelper(eventLocation, seg); // returns mock event elements
        },
        // Unrenders any visual indication of an event being resized
        unrenderEventResize: function () {
            this.unrenderHelper();
        },
        /* Event Helper
         ------------------------------------------------------------------------------------------------------------------*/


        // Renders a mock "helper" event. `sourceSeg` is the original segment object and might be null (an external drag)
        renderHelper: function (event, sourceSeg) {
            return this.renderHelperSegs(this.eventToSegs(event), sourceSeg); // returns mock event elements
        },
        // Unrenders any mock helper event
        unrenderHelper: function () {
            this.unrenderHelperSegs();
        },
        /* Business Hours
         ------------------------------------------------------------------------------------------------------------------*/


        renderBusinessHours: function () {
            var events = this.view.calendar.getBusinessHoursEvents();
            var segs = this.eventsToSegs(events);

            this.renderBusinessSegs(segs);
        },
        unrenderBusinessHours: function () {
            this.unrenderBusinessSegs();
        },
        /* Now Indicator
         ------------------------------------------------------------------------------------------------------------------*/


        getNowIndicatorUnit: function () {
            return 'minute'; // will refresh on the minute
        },
        renderNowIndicator: function (date) {
            // seg system might be overkill, but it handles scenario where line needs to be rendered
            //  more than once because of columns with the same date (resources columns for example)
            var segs = this.spanToSegs({start: date, end: date});
            var top = this.computeDateTop(date, date);
            var nodes = [];
            var i;

            // render lines within the columns
            for (i = 0; i < segs.length; i++) {
                nodes.push($('<div class="fc-now-indicator fc-now-indicator-line"></div>')
                        .css('top', top)
                        .appendTo(this.colContainerEls.eq(segs[i].col))[0]);
            }

            // render an arrow over the axis
            if (segs.length > 0) { // is the current time in view?
                nodes.push($('<div class="fc-now-indicator fc-now-indicator-arrow"></div>')
                        .css('top', top)
                        .appendTo(this.el.find('.fc-content-skeleton'))[0]);
            }

            this.nowIndicatorEls = $(nodes);
        },
        unrenderNowIndicator: function () {
            if (this.nowIndicatorEls) {
                this.nowIndicatorEls.remove();
                this.nowIndicatorEls = null;
            }
        },
        /* Selection
         ------------------------------------------------------------------------------------------------------------------*/


        // Renders a visual indication of a selection. Overrides the default, which was to simply render a highlight.
        renderSelection: function (span) {
            if (this.view.opt('selectHelper')) { // this setting signals that a mock helper event should be rendered

                // normally acceps an eventLocation, span has a start/end, which is good enough
                this.renderEventLocationHelper(span);
            } else {
                this.renderHighlight(span);
            }
        },
        // Unrenders any visual indication of a selection
        unrenderSelection: function () {
            this.unrenderHelper();
            this.unrenderHighlight();
        },
        /* Highlight
         ------------------------------------------------------------------------------------------------------------------*/


        renderHighlight: function (span) {
            this.renderHighlightSegs(this.spanToSegs(span));
        },
        unrenderHighlight: function () {
            this.unrenderHighlightSegs();
        }

    });

    ;
    ;

    /* Methods for rendering SEGMENTS, pieces of content that live on the view
     ( this file is no longer just for events )
     ----------------------------------------------------------------------------------------------------------------------*/

    TimeGrid.mixin({
        colContainerEls: null, // containers for each column

        // inner-containers for each column where different types of segs live
        fgContainerEls: null,
        bgContainerEls: null,
        helperContainerEls: null,
        highlightContainerEls: null,
        businessContainerEls: null,
        // arrays of different types of displayed segments
        fgSegs: null,
        bgSegs: null,
        helperSegs: null,
        highlightSegs: null,
        businessSegs: null,
        // Renders the DOM that the view's content will live in
        renderContentSkeleton: function () {
            var cellHtml = '';
            var i;
            var skeletonEl;

            for (i = 0; i < this.colCnt; i++) {
                cellHtml +=
                        '<td>' +
                        '<div class="fc-content-col">' +
                        '<div class="fc-event-container fc-helper-container"></div>' +
                        '<div class="fc-event-container"></div>' +
                        '<div class="fc-highlight-container"></div>' +
                        '<div class="fc-bgevent-container"></div>' +
                        '<div class="fc-business-container"></div>' +
                        '</div>' +
                        '</td>';
            }

            skeletonEl = $(
                    '<div class="fc-content-skeleton">' +
                    '<table>' +
                    '<tr>' + cellHtml + '</tr>' +
                    '</table>' +
                    '</div>'
                    );

            this.colContainerEls = skeletonEl.find('.fc-content-col');
            this.helperContainerEls = skeletonEl.find('.fc-helper-container');
            this.fgContainerEls = skeletonEl.find('.fc-event-container:not(.fc-helper-container)');
            this.bgContainerEls = skeletonEl.find('.fc-bgevent-container');
            this.highlightContainerEls = skeletonEl.find('.fc-highlight-container');
            this.businessContainerEls = skeletonEl.find('.fc-business-container');

            this.bookendCells(skeletonEl.find('tr')); // TODO: do this on string level
            this.el.append(skeletonEl);
        },
        /* Foreground Events
         ------------------------------------------------------------------------------------------------------------------*/


        renderFgSegs: function (segs) {
            segs = this.renderFgSegsIntoContainers(segs, this.fgContainerEls);
            this.fgSegs = segs;
            return segs; // needed for Grid::renderEvents
        },
        unrenderFgSegs: function () {
            this.unrenderNamedSegs('fgSegs');
        },
        /* Foreground Helper Events
         ------------------------------------------------------------------------------------------------------------------*/


        renderHelperSegs: function (segs, sourceSeg) {
            var helperEls = [];
            var i, seg;
            var sourceEl;

            segs = this.renderFgSegsIntoContainers(segs, this.helperContainerEls);

            // Try to make the segment that is in the same row as sourceSeg look the same
            for (i = 0; i < segs.length; i++) {
                seg = segs[i];
                if (sourceSeg && sourceSeg.col === seg.col) {
                    sourceEl = sourceSeg.el;
                    seg.el.css({
                        left: sourceEl.css('left'),
                        right: sourceEl.css('right'),
                        'margin-left': sourceEl.css('margin-left'),
                        'margin-right': sourceEl.css('margin-right')
                    });
                }
                helperEls.push(seg.el[0]);
            }

            this.helperSegs = segs;

            return $(helperEls); // must return rendered helpers
        },
        unrenderHelperSegs: function () {
            this.unrenderNamedSegs('helperSegs');
        },
        /* Background Events
         ------------------------------------------------------------------------------------------------------------------*/


        renderBgSegs: function (segs) {
            segs = this.renderFillSegEls('bgEvent', segs); // TODO: old fill system
            this.updateSegVerticals(segs);
            this.attachSegsByCol(this.groupSegsByCol(segs), this.bgContainerEls);
            this.bgSegs = segs;
            return segs; // needed for Grid::renderEvents
        },
        unrenderBgSegs: function () {
            this.unrenderNamedSegs('bgSegs');
        },
        /* Highlight
         ------------------------------------------------------------------------------------------------------------------*/


        renderHighlightSegs: function (segs) {
            segs = this.renderFillSegEls('highlight', segs); // TODO: old fill system
            this.updateSegVerticals(segs);
            this.attachSegsByCol(this.groupSegsByCol(segs), this.highlightContainerEls);
            this.highlightSegs = segs;
        },
        unrenderHighlightSegs: function () {
            this.unrenderNamedSegs('highlightSegs');
        },
        /* Business Hours
         ------------------------------------------------------------------------------------------------------------------*/


        renderBusinessSegs: function (segs) {
            segs = this.renderFillSegEls('businessHours', segs); // TODO: old fill system
            this.updateSegVerticals(segs);
            this.attachSegsByCol(this.groupSegsByCol(segs), this.businessContainerEls);
            this.businessSegs = segs;
        },
        unrenderBusinessSegs: function () {
            this.unrenderNamedSegs('businessSegs');
        },
        /* Seg Rendering Utils
         ------------------------------------------------------------------------------------------------------------------*/


        // Given a flat array of segments, return an array of sub-arrays, grouped by each segment's col
        groupSegsByCol: function (segs) {
            var segsByCol = [];
            var i;

            for (i = 0; i < this.colCnt; i++) {
                segsByCol.push([]);
            }

            for (i = 0; i < segs.length; i++) {
                segsByCol[segs[i].col].push(segs[i]);
            }

            return segsByCol;
        },
        // Given segments grouped by column, insert the segments' elements into a parallel array of container
        // elements, each living within a column.
        attachSegsByCol: function (segsByCol, containerEls) {
            var col;
            var segs;
            var i;

            for (col = 0; col < this.colCnt; col++) { // iterate each column grouping
                segs = segsByCol[col];

                for (i = 0; i < segs.length; i++) {
                    containerEls.eq(col).append(segs[i].el);
                }
            }
        },
        // Given the name of a property of `this` object, assumed to be an array of segments,
        // loops through each segment and removes from DOM. Will null-out the property afterwards.
        unrenderNamedSegs: function (propName) {
            var segs = this[propName];
            var i;

            if (segs) {
                for (i = 0; i < segs.length; i++) {
                    segs[i].el.remove();
                }
                this[propName] = null;
            }
        },
        /* Foreground Event Rendering Utils
         ------------------------------------------------------------------------------------------------------------------*/


        // Given an array of foreground segments, render a DOM element for each, computes position,
        // and attaches to the column inner-container elements.
        renderFgSegsIntoContainers: function (segs, containerEls) {
            var segsByCol;
            var col;

            segs = this.renderFgSegEls(segs); // will call fgSegHtml
            segsByCol = this.groupSegsByCol(segs);

            for (col = 0; col < this.colCnt; col++) {
                this.updateFgSegCoords(segsByCol[col]);
            }

            this.attachSegsByCol(segsByCol, containerEls);

            return segs;
        },
        // Renders the HTML for a single event segment's default rendering
        fgSegHtml: function (seg, disableResizing) {
            var view = this.view;
            var event = seg.event;
            var isDraggable = view.isEventDraggable(event);
            var isResizableFromStart = !disableResizing && seg.isStart && view.isEventResizableFromStart(event);
            var isResizableFromEnd = !disableResizing && seg.isEnd && view.isEventResizableFromEnd(event);
            var classes = this.getSegClasses(seg, isDraggable, isResizableFromStart || isResizableFromEnd);
            var skinCss = cssToStr(this.getSegSkinCss(seg));
            var timeText;
            var fullTimeText; // more verbose time text. for the print stylesheet
            var startTimeText; // just the start time text

            classes.unshift('fc-time-grid-event', 'fc-v-event');

            if (view.isMultiDayEvent(event)) { // if the event appears to span more than one day...
                // Don't display time text on segments that run entirely through a day.
                // That would appear as midnight-midnight and would look dumb.
                // Otherwise, display the time text for the *segment's* times (like 6pm-midnight or midnight-10am)
                if (seg.isStart || seg.isEnd) {
                    timeText = this.getEventTimeText(seg);
                    fullTimeText = this.getEventTimeText(seg, 'LT');
                    startTimeText = this.getEventTimeText(seg, null, false); // displayEnd=false
                }
            } else {
                // Display the normal time text for the *event's* times
                timeText = this.getEventTimeText(event);
                fullTimeText = this.getEventTimeText(event, 'LT');
                startTimeText = this.getEventTimeText(event, null, false); // displayEnd=false
            }

            return '<a class="' + classes.join(' ') + '"' +
                    (event.url ?
                            ' href="' + htmlEscape(event.url) + '"' :
                            ''
                            ) +
                    (skinCss ?
                            ' style="' + skinCss + '"' :
                            ''
                            ) +
                    '>' +
                    '<div class="fc-content">' +
                    (timeText ?
                            '<div class="fc-time"' +
                            ' data-start="' + htmlEscape(startTimeText) + '"' +
                            ' data-full="' + htmlEscape(fullTimeText) + '"' +
                            '>' +
                            '<span>' + htmlEscape(timeText) + '</span>' +
                            '</div>' :
                            ''
                            ) +
                    (event.title ?
                            '<div class="fc-title">' +
                            htmlEscape(event.title) +
                            '</div>' :
                            ''
                            ) +
                    '</div>' +
                    '<div class="fc-bg"/>' +
                    /* TODO: write CSS for this
                     (isResizableFromStart ?
                     '<div class="fc-resizer fc-start-resizer" />' :
                     ''
                     ) +
                     */
                            (isResizableFromEnd ?
                                    '<div class="fc-resizer fc-end-resizer" />' :
                                    ''
                                    ) +
                            '</a>';
                },
                /* Seg Position Utils
                 ------------------------------------------------------------------------------------------------------------------*/


                // Refreshes the CSS top/bottom coordinates for each segment element.
                // Works when called after initial render, after a window resize/zoom for example.
                updateSegVerticals: function (segs) {
                    this.computeSegVerticals(segs);
                    this.assignSegVerticals(segs);
                },
                // For each segment in an array, computes and assigns its top and bottom properties
                computeSegVerticals: function (segs) {
                    var i, seg;

                    for (i = 0; i < segs.length; i++) {
                        seg = segs[i];
                        seg.top = this.computeDateTop(seg.start, seg.start);
                        seg.bottom = this.computeDateTop(seg.end, seg.start);
                    }
                },
                // Given segments that already have their top/bottom properties computed, applies those values to
                // the segments' elements.
                assignSegVerticals: function (segs) {
                    var i, seg;

                    for (i = 0; i < segs.length; i++) {
                        seg = segs[i];
                        seg.el.css(this.generateSegVerticalCss(seg));
                    }
                },
                // Generates an object with CSS properties for the top/bottom coordinates of a segment element
                generateSegVerticalCss: function (seg) {
                    return {
                        top: seg.top,
                        bottom: -seg.bottom // flipped because needs to be space beyond bottom edge of event container
                    };
                },
                /* Foreground Event Positioning Utils
                 ------------------------------------------------------------------------------------------------------------------*/


                // Given segments that are assumed to all live in the *same column*,
                // compute their verical/horizontal coordinates and assign to their elements.
                updateFgSegCoords: function (segs) {
                    this.computeSegVerticals(segs); // horizontals relies on this
                    this.computeFgSegHorizontals(segs); // compute horizontal coordinates, z-index's, and reorder the array
                    this.assignSegVerticals(segs);
                    this.assignFgSegHorizontals(segs);
                },
                // Given an array of segments that are all in the same column, sets the backwardCoord and forwardCoord on each.
                // NOTE: Also reorders the given array by date!
                computeFgSegHorizontals: function (segs) {
                    var levels;
                    var level0;
                    var i;

                    this.sortEventSegs(segs); // order by certain criteria
                    levels = buildSlotSegLevels(segs);
                    computeForwardSlotSegs(levels);

                    if ((level0 = levels[0])) {

                        for (i = 0; i < level0.length; i++) {
                            computeSlotSegPressures(level0[i]);
                        }

                        for (i = 0; i < level0.length; i++) {
                            this.computeFgSegForwardBack(level0[i], 0, 0);
                        }
                    }
                },
                // Calculate seg.forwardCoord and seg.backwardCoord for the segment, where both values range
                // from 0 to 1. If the calendar is left-to-right, the seg.backwardCoord maps to "left" and
                // seg.forwardCoord maps to "right" (via percentage). Vice-versa if the calendar is right-to-left.
                //
                // The segment might be part of a "series", which means consecutive segments with the same pressure
                // who's width is unknown until an edge has been hit. `seriesBackwardPressure` is the number of
                // segments behind this one in the current series, and `seriesBackwardCoord` is the starting
                // coordinate of the first segment in the series.
                computeFgSegForwardBack: function (seg, seriesBackwardPressure, seriesBackwardCoord) {
                    var forwardSegs = seg.forwardSegs;
                    var i;

                    if (seg.forwardCoord === undefined) { // not already computed

                        if (!forwardSegs.length) {

                            // if there are no forward segments, this segment should butt up against the edge
                            seg.forwardCoord = 1;
                        } else {

                            // sort highest pressure first
                            this.sortForwardSegs(forwardSegs);

                            // this segment's forwardCoord will be calculated from the backwardCoord of the
                            // highest-pressure forward segment.
                            this.computeFgSegForwardBack(forwardSegs[0], seriesBackwardPressure + 1, seriesBackwardCoord);
                            seg.forwardCoord = forwardSegs[0].backwardCoord;
                        }

                        // calculate the backwardCoord from the forwardCoord. consider the series
                        seg.backwardCoord = seg.forwardCoord -
                                (seg.forwardCoord - seriesBackwardCoord) / // available width for series
                                (seriesBackwardPressure + 1); // # of segments in the series

                        // use this segment's coordinates to computed the coordinates of the less-pressurized
                        // forward segments
                        for (i = 0; i < forwardSegs.length; i++) {
                            this.computeFgSegForwardBack(forwardSegs[i], 0, seg.forwardCoord);
                        }
                    }
                },
                sortForwardSegs: function (forwardSegs) {
                    forwardSegs.sort(proxy(this, 'compareForwardSegs'));
                },
                // A cmp function for determining which forward segment to rely on more when computing coordinates.
                compareForwardSegs: function (seg1, seg2) {
                    // put higher-pressure first
                    return seg2.forwardPressure - seg1.forwardPressure ||
                            // put segments that are closer to initial edge first (and favor ones with no coords yet)
                                    (seg1.backwardCoord || 0) - (seg2.backwardCoord || 0) ||
                                    // do normal sorting...
                                    this.compareEventSegs(seg1, seg2);
                        },
                        // Given foreground event segments that have already had their position coordinates computed,
                        // assigns position-related CSS values to their elements.
                        assignFgSegHorizontals: function (segs) {
                            var i, seg;

                            for (i = 0; i < segs.length; i++) {
                                seg = segs[i];
                                seg.el.css(this.generateFgSegHorizontalCss(seg));

                                // if the height is short, add a className for alternate styling
                                if (seg.bottom - seg.top < 30) {
                                    seg.el.addClass('fc-short');
                                }
                            }
                        },
                        // Generates an object with CSS properties/values that should be applied to an event segment element.
                        // Contains important positioning-related properties that should be applied to any event element, customized or not.
                        generateFgSegHorizontalCss: function (seg) {
                            var shouldOverlap = this.view.opt('slotEventOverlap');
                            var backwardCoord = seg.backwardCoord; // the left side if LTR. the right side if RTL. floating-point
                            var forwardCoord = seg.forwardCoord; // the right side if LTR. the left side if RTL. floating-point
                            var props = this.generateSegVerticalCss(seg); // get top/bottom first
                            var left; // amount of space from left edge, a fraction of the total width
                            var right; // amount of space from right edge, a fraction of the total width

                            if (shouldOverlap) {
                                // double the width, but don't go beyond the maximum forward coordinate (1.0)
                                forwardCoord = Math.min(1, backwardCoord + (forwardCoord - backwardCoord) * 2);
                            }

                            if (this.isRTL) {
                                left = 1 - forwardCoord;
                                right = backwardCoord;
                            } else {
                                left = backwardCoord;
                                right = 1 - forwardCoord;
                            }

                            props.zIndex = seg.level + 1; // convert from 0-base to 1-based
                            props.left = left * 100 + '%';
                            props.right = right * 100 + '%';

                            if (shouldOverlap && seg.forwardPressure) {
                                // add padding to the edge so that forward stacked events don't cover the resizer's icon
                                props[this.isRTL ? 'marginLeft' : 'marginRight'] = 10 * 2; // 10 is a guesstimate of the icon's width
                            }

                            return props;
                        }

                    });


// Builds an array of segments "levels". The first level will be the leftmost tier of segments if the calendar is
// left-to-right, or the rightmost if the calendar is right-to-left. Assumes the segments are already ordered by date.
            function buildSlotSegLevels(segs) {
                var levels = [];
                var i, seg;
                var j;

                for (i = 0; i < segs.length; i++) {
                    seg = segs[i];

                    // go through all the levels and stop on the first level where there are no collisions
                    for (j = 0; j < levels.length; j++) {
                        if (!computeSlotSegCollisions(seg, levels[j]).length) {
                            break;
                        }
                    }

                    seg.level = j;

                    (levels[j] || (levels[j] = [])).push(seg);
                }

                return levels;
            }


// For every segment, figure out the other segments that are in subsequent
// levels that also occupy the same vertical space. Accumulate in seg.forwardSegs
            function computeForwardSlotSegs(levels) {
                var i, level;
                var j, seg;
                var k;

                for (i = 0; i < levels.length; i++) {
                    level = levels[i];

                    for (j = 0; j < level.length; j++) {
                        seg = level[j];

                        seg.forwardSegs = [];
                        for (k = i + 1; k < levels.length; k++) {
                            computeSlotSegCollisions(seg, levels[k], seg.forwardSegs);
                        }
                    }
                }
            }


// Figure out which path forward (via seg.forwardSegs) results in the longest path until
// the furthest edge is reached. The number of segments in this path will be seg.forwardPressure
            function computeSlotSegPressures(seg) {
                var forwardSegs = seg.forwardSegs;
                var forwardPressure = 0;
                var i, forwardSeg;

                if (seg.forwardPressure === undefined) { // not already computed

                    for (i = 0; i < forwardSegs.length; i++) {
                        forwardSeg = forwardSegs[i];

                        // figure out the child's maximum forward path
                        computeSlotSegPressures(forwardSeg);

                        // either use the existing maximum, or use the child's forward pressure
                        // plus one (for the forwardSeg itself)
                        forwardPressure = Math.max(
                                forwardPressure,
                                1 + forwardSeg.forwardPressure
                                );
                    }

                    seg.forwardPressure = forwardPressure;
                }
            }


// Find all the segments in `otherSegs` that vertically collide with `seg`.
// Append into an optionally-supplied `results` array and return.
            function computeSlotSegCollisions(seg, otherSegs, results) {
                results = results || [];

                for (var i = 0; i < otherSegs.length; i++) {
                    if (isSlotSegCollision(seg, otherSegs[i])) {
                        results.push(otherSegs[i]);
                    }
                }

                return results;
            }


// Do these segments occupy the same vertical space?
            function isSlotSegCollision(seg1, seg2) {
                return seg1.bottom > seg2.top && seg1.top < seg2.bottom;
            }

            ;
            ;

            /* An abstract class from which other views inherit from
             ----------------------------------------------------------------------------------------------------------------------*/

            var View = FC.View = Class.extend(EmitterMixin, ListenerMixin, {
                type: null, // subclass' view name (string)
                name: null, // deprecated. use `type` instead
                title: null, // the text that will be displayed in the header's title

                calendar: null, // owner Calendar object
                options: null, // hash containing all options. already merged with view-specific-options
                el: null, // the view's containing element. set by Calendar

                displaying: null, // a promise representing the state of rendering. null if no render requested
                isSkeletonRendered: false,
                isEventsRendered: false,
                // range the view is actually displaying (moments)
                start: null,
                end: null, // exclusive

                // range the view is formally responsible for (moments)
                // may be different from start/end. for example, a month view might have 1st-31st, excluding padded dates
                intervalStart: null,
                intervalEnd: null, // exclusive
                intervalDuration: null,
                intervalUnit: null, // name of largest unit being displayed, like "month" or "week"

                isRTL: false,
                isSelected: false, // boolean whether a range of time is user-selected or not
                selectedEvent: null,
                eventOrderSpecs: null, // criteria for ordering events when they have same date/time

                // classNames styled by jqui themes
                widgetHeaderClass: null,
                widgetContentClass: null,
                highlightStateClass: null,
                // for date utils, computed from options
                nextDayThreshold: null,
                isHiddenDayHash: null,
                // now indicator
                isNowIndicatorRendered: null,
                initialNowDate: null, // result first getNow call
                initialNowQueriedMs: null, // ms time the getNow was called
                nowIndicatorTimeoutID: null, // for refresh timing of now indicator
                nowIndicatorIntervalID: null, // "


                constructor: function (calendar, type, options, intervalDuration) {

                    this.calendar = calendar;
                    this.type = this.name = type; // .name is deprecated
                    this.options = options;
                    this.intervalDuration = intervalDuration || moment.duration(1, 'day');

                    this.nextDayThreshold = moment.duration(this.opt('nextDayThreshold'));
                    this.initThemingProps();
                    this.initHiddenDays();
                    this.isRTL = this.opt('isRTL');

                    this.eventOrderSpecs = parseFieldSpecs(this.opt('eventOrder'));

                    this.initialize();
                },
                // A good place for subclasses to initialize member variables
                initialize: function () {
                    // subclasses can implement
                },
                // Retrieves an option with the given name
                opt: function (name) {
                    return this.options[name];
                },
                // Triggers handlers that are view-related. Modifies args before passing to calendar.
                trigger: function (name, thisObj) { // arguments beyond thisObj are passed along
                    var calendar = this.calendar;

                    return calendar.trigger.apply(
                            calendar,
                            [name, thisObj || this].concat(
                            Array.prototype.slice.call(arguments, 2), // arguments beyond thisObj
                            [this] // always make the last argument a reference to the view. TODO: deprecate
                            )
                            );
                },
                /* Dates
                 ------------------------------------------------------------------------------------------------------------------*/


                // Updates all internal dates to center around the given current unzoned date.
                setDate: function (date) {
                    this.setRange(this.computeRange(date));
                },
                // Updates all internal dates for displaying the given unzoned range.
                setRange: function (range) {
                    $.extend(this, range); // assigns every property to this object's member variables
                    this.updateTitle();
                },
                // Given a single current unzoned date, produce information about what range to display.
                // Subclasses can override. Must return all properties.
                computeRange: function (date) {
                    var intervalUnit = computeIntervalUnit(this.intervalDuration);
                    var intervalStart = date.clone().startOf(intervalUnit);
                    var intervalEnd = intervalStart.clone().add(this.intervalDuration);
                    var start, end;

                    // normalize the range's time-ambiguity
                    if (/year|month|week|day/.test(intervalUnit)) { // whole-days?
                        intervalStart.stripTime();
                        intervalEnd.stripTime();
                    } else { // needs to have a time?
                        if (!intervalStart.hasTime()) {
                            intervalStart = this.calendar.time(0); // give 00:00 time
                        }
                        if (!intervalEnd.hasTime()) {
                            intervalEnd = this.calendar.time(0); // give 00:00 time
                        }
                    }

                    start = intervalStart.clone();
                    start = this.skipHiddenDays(start);
                    end = intervalEnd.clone();
                    end = this.skipHiddenDays(end, -1, true); // exclusively move backwards

                    return {
                        intervalUnit: intervalUnit,
                        intervalStart: intervalStart,
                        intervalEnd: intervalEnd,
                        start: start,
                        end: end
                    };
                },
                // Computes the new date when the user hits the prev button, given the current date
                computePrevDate: function (date) {
                    return this.massageCurrentDate(
                            date.clone().startOf(this.intervalUnit).subtract(this.intervalDuration), -1
                            );
                },
                // Computes the new date when the user hits the next button, given the current date
                computeNextDate: function (date) {
                    return this.massageCurrentDate(
                            date.clone().startOf(this.intervalUnit).add(this.intervalDuration)
                            );
                },
                // Given an arbitrarily calculated current date of the calendar, returns a date that is ensured to be completely
                // visible. `direction` is optional and indicates which direction the current date was being
                // incremented or decremented (1 or -1).
                massageCurrentDate: function (date, direction) {
                    if (this.intervalDuration.as('days') <= 1) { // if the view displays a single day or smaller
                        if (this.isHiddenDay(date)) {
                            date = this.skipHiddenDays(date, direction);
                            date.startOf('day');
                        }
                    }

                    return date;
                },
                /* Title and Date Formatting
                 ------------------------------------------------------------------------------------------------------------------*/


                // Sets the view's title property to the most updated computed value
                updateTitle: function () {
                    this.title = this.computeTitle();
                },
                // Computes what the title at the top of the calendar should be for this view
                computeTitle: function () {
                    return this.formatRange(
                            {
                                // in case intervalStart/End has a time, make sure timezone is correct
                                start: this.calendar.applyTimezone(this.intervalStart),
                                end: this.calendar.applyTimezone(this.intervalEnd)
                            },
                            this.opt('titleFormat') || this.computeTitleFormat(),
                            this.opt('titleRangeSeparator')
                            );
                },
                // Generates the format string that should be used to generate the title for the current date range.
                // Attempts to compute the most appropriate format if not explicitly specified with `titleFormat`.
                computeTitleFormat: function () {
                    if (this.intervalUnit == 'year') {
                        return 'YYYY';
                    } else if (this.intervalUnit == 'month') {
                        return this.opt('monthYearFormat'); // like "September 2014"
                    } else if (this.intervalDuration.as('days') > 1) {
                        return 'll'; // multi-day range. shorter, like "Sep 9 - 10 2014"
                    } else {
                        return 'LL'; // one day. longer, like "September 9 2014"
                    }
                },
                // Utility for formatting a range. Accepts a range object, formatting string, and optional separator.
                // Displays all-day ranges naturally, with an inclusive end. Takes the current isRTL into account.
                // The timezones of the dates within `range` will be respected.
                formatRange: function (range, formatStr, separator) {
                    var end = range.end;

                    if (!end.hasTime()) { // all-day?
                        end = end.clone().subtract(1); // convert to inclusive. last ms of previous day
                    }

                    return formatRange(range.start, end, formatStr, separator, this.opt('isRTL'));
                },
                /* Rendering
                 ------------------------------------------------------------------------------------------------------------------*/


                // Sets the container element that the view should render inside of.
                // Does other DOM-related initializations.
                setElement: function (el) {
                    this.el = el;
                    this.bindGlobalHandlers();
                },
                // Removes the view's container element from the DOM, clearing any content beforehand.
                // Undoes any other DOM-related attachments.
                removeElement: function () {
                    this.clear(); // clears all content

                    // clean up the skeleton
                    if (this.isSkeletonRendered) {
                        this.unrenderSkeleton();
                        this.isSkeletonRendered = false;
                    }

                    this.unbindGlobalHandlers();

                    this.el.remove();

                    // NOTE: don't null-out this.el in case the View was destroyed within an API callback.
                    // We don't null-out the View's other jQuery element references upon destroy,
                    //  so we shouldn't kill this.el either.
                },
                // Does everything necessary to display the view centered around the given unzoned date.
                // Does every type of rendering EXCEPT rendering events.
                // Is asychronous and returns a promise.
                display: function (date) {
                    var _this = this;
                    var scrollState = null;

                    if (this.displaying) {
                        scrollState = this.queryScroll();
                    }

                    this.calendar.freezeContentHeight();

                    return syncThen(this.clear(), function () { // clear the content first
                        return (
                                _this.displaying =
                                syncThen(_this.displayView(date), function () { // displayView might return a promise
                                    _this.forceScroll(_this.computeInitialScroll(scrollState));
                                    _this.calendar.unfreezeContentHeight();
                                    _this.triggerRender();
                                })
                                );
                    });
                },
                // Does everything necessary to clear the content of the view.
                // Clears dates and events. Does not clear the skeleton.
                // Is asychronous and returns a promise.
                clear: function () {
                    var _this = this;
                    var displaying = this.displaying;

                    if (displaying) { // previously displayed, or in the process of being displayed?
                        return syncThen(displaying, function () { // wait for the display to finish
                            _this.displaying = null;
                            _this.clearEvents();
                            return _this.clearView(); // might return a promise. chain it
                        });
                    } else {
                        return $.when(); // an immediately-resolved promise
                    }
                },
                // Displays the view's non-event content, such as date-related content or anything required by events.
                // Renders the view's non-content skeleton if necessary.
                // Can be asynchronous and return a promise.
                displayView: function (date) {
                    if (!this.isSkeletonRendered) {
                        this.renderSkeleton();
                        this.isSkeletonRendered = true;
                    }
                    if (date) {
                        this.setDate(date);
                    }
                    if (this.render) {
                        this.render(); // TODO: deprecate
                    }
                    this.renderDates();
                    this.updateSize();
                    this.renderBusinessHours(); // might need coordinates, so should go after updateSize()
                    this.startNowIndicator();
                },
                // Unrenders the view content that was rendered in displayView.
                // Can be asynchronous and return a promise.
                clearView: function () {
                    this.unselect();
                    this.stopNowIndicator();
                    this.triggerUnrender();
                    this.unrenderBusinessHours();
                    this.unrenderDates();
                    if (this.destroy) {
                        this.destroy(); // TODO: deprecate
                    }
                },
                // Renders the basic structure of the view before any content is rendered
                renderSkeleton: function () {
                    // subclasses should implement
                },
                // Unrenders the basic structure of the view
                unrenderSkeleton: function () {
                    // subclasses should implement
                },
                // Renders the view's date-related content.
                // Assumes setRange has already been called and the skeleton has already been rendered.
                renderDates: function () {
                    // subclasses should implement
                },
                // Unrenders the view's date-related content
                unrenderDates: function () {
                    // subclasses should override
                },
                // Signals that the view's content has been rendered
                triggerRender: function () {
                    this.trigger('viewRender', this, this, this.el);
                },
                // Signals that the view's content is about to be unrendered
                triggerUnrender: function () {
                    this.trigger('viewDestroy', this, this, this.el);
                },
                // Binds DOM handlers to elements that reside outside the view container, such as the document
                bindGlobalHandlers: function () {
                    this.listenTo($(document), 'mousedown', this.handleDocumentMousedown);
                    this.listenTo($(document), 'touchstart', this.processUnselect);
                },
                // Unbinds DOM handlers from elements that reside outside the view container
                unbindGlobalHandlers: function () {
                    this.stopListeningTo($(document));
                },
                // Initializes internal variables related to theming
                initThemingProps: function () {
                    var tm = this.opt('theme') ? 'ui' : 'fc';

                    this.widgetHeaderClass = tm + '-widget-header';
                    this.widgetContentClass = tm + '-widget-content';
                    this.highlightStateClass = tm + '-state-highlight';
                },
                /* Business Hours
                 ------------------------------------------------------------------------------------------------------------------*/


                // Renders business-hours onto the view. Assumes updateSize has already been called.
                renderBusinessHours: function () {
                    // subclasses should implement
                },
                // Unrenders previously-rendered business-hours
                unrenderBusinessHours: function () {
                    // subclasses should implement
                },
                /* Now Indicator
                 ------------------------------------------------------------------------------------------------------------------*/


                // Immediately render the current time indicator and begins re-rendering it at an interval,
                // which is defined by this.getNowIndicatorUnit().
                // TODO: somehow do this for the current whole day's background too
                startNowIndicator: function () {
                    var _this = this;
                    var unit;
                    var update;
                    var delay; // ms wait value

                    if (this.opt('nowIndicator')) {
                        unit = this.getNowIndicatorUnit();
                        if (unit) {
                            update = proxy(this, 'updateNowIndicator'); // bind to `this`

                            this.initialNowDate = this.calendar.getNow();
                            this.initialNowQueriedMs = +new Date();
                            this.renderNowIndicator(this.initialNowDate);
                            this.isNowIndicatorRendered = true;

                            // wait until the beginning of the next interval
                            delay = this.initialNowDate.clone().startOf(unit).add(1, unit) - this.initialNowDate;
                            this.nowIndicatorTimeoutID = setTimeout(function () {
                                _this.nowIndicatorTimeoutID = null;
                                update();
                                delay = +moment.duration(1, unit);
                                delay = Math.max(100, delay); // prevent too frequent
                                _this.nowIndicatorIntervalID = setInterval(update, delay); // update every interval
                            }, delay);
                        }
                    }
                },
                // rerenders the now indicator, computing the new current time from the amount of time that has passed
                // since the initial getNow call.
                updateNowIndicator: function () {
                    if (this.isNowIndicatorRendered) {
                        this.unrenderNowIndicator();
                        this.renderNowIndicator(
                                this.initialNowDate.clone().add(new Date() - this.initialNowQueriedMs) // add ms
                                );
                    }
                },
                // Immediately unrenders the view's current time indicator and stops any re-rendering timers.
                // Won't cause side effects if indicator isn't rendered.
                stopNowIndicator: function () {
                    if (this.isNowIndicatorRendered) {

                        if (this.nowIndicatorTimeoutID) {
                            clearTimeout(this.nowIndicatorTimeoutID);
                            this.nowIndicatorTimeoutID = null;
                        }
                        if (this.nowIndicatorIntervalID) {
                            clearTimeout(this.nowIndicatorIntervalID);
                            this.nowIndicatorIntervalID = null;
                        }

                        this.unrenderNowIndicator();
                        this.isNowIndicatorRendered = false;
                    }
                },
                // Returns a string unit, like 'second' or 'minute' that defined how often the current time indicator
                // should be refreshed. If something falsy is returned, no time indicator is rendered at all.
                getNowIndicatorUnit: function () {
                    // subclasses should implement
                },
                // Renders a current time indicator at the given datetime
                renderNowIndicator: function (date) {
                    // subclasses should implement
                },
                // Undoes the rendering actions from renderNowIndicator
                unrenderNowIndicator: function () {
                    // subclasses should implement
                },
                /* Dimensions
                 ------------------------------------------------------------------------------------------------------------------*/


                // Refreshes anything dependant upon sizing of the container element of the grid
                updateSize: function (isResize) {
                    var scrollState;

                    if (isResize) {
                        scrollState = this.queryScroll();
                    }

                    this.updateHeight(isResize);
                    this.updateWidth(isResize);
                    this.updateNowIndicator();

                    if (isResize) {
                        this.setScroll(scrollState);
                    }
                },
                // Refreshes the horizontal dimensions of the calendar
                updateWidth: function (isResize) {
                    // subclasses should implement
                },
                // Refreshes the vertical dimensions of the calendar
                updateHeight: function (isResize) {
                    var calendar = this.calendar; // we poll the calendar for height information

                    this.setHeight(
                            calendar.getSuggestedViewHeight(),
                            calendar.isHeightAuto()
                            );
                },
                // Updates the vertical dimensions of the calendar to the specified height.
                // if `isAuto` is set to true, height becomes merely a suggestion and the view should use its "natural" height.
                setHeight: function (height, isAuto) {
                    // subclasses should implement
                },
                /* Scroller
                 ------------------------------------------------------------------------------------------------------------------*/


                // Computes the initial pre-configured scroll state prior to allowing the user to change it.
                // Given the scroll state from the previous rendering. If first time rendering, given null.
                computeInitialScroll: function (previousScrollState) {
                    return 0;
                },
                // Retrieves the view's current natural scroll state. Can return an arbitrary format.
                queryScroll: function () {
                    // subclasses must implement
                },
                // Sets the view's scroll state. Will accept the same format computeInitialScroll and queryScroll produce.
                setScroll: function (scrollState) {
                    // subclasses must implement
                },
                // Sets the scroll state, making sure to overcome any predefined scroll value the browser has in mind
                forceScroll: function (scrollState) {
                    var _this = this;

                    this.setScroll(scrollState);
                    setTimeout(function () {
                        _this.setScroll(scrollState);
                    }, 0);
                },
                /* Event Elements / Segments
                 ------------------------------------------------------------------------------------------------------------------*/


                // Does everything necessary to display the given events onto the current view
                displayEvents: function (events) {
                    var scrollState = this.queryScroll();

                    this.clearEvents();
                    this.renderEvents(events);
                    this.isEventsRendered = true;
                    this.setScroll(scrollState);
                    this.triggerEventRender();
                },
                // Does everything necessary to clear the view's currently-rendered events
                clearEvents: function () {
                    var scrollState;

                    if (this.isEventsRendered) {

                        // TODO: optimize: if we know this is part of a displayEvents call, don't queryScroll/setScroll
                        scrollState = this.queryScroll();

                        this.triggerEventUnrender();
                        if (this.destroyEvents) {
                            this.destroyEvents(); // TODO: deprecate
                        }
                        this.unrenderEvents();
                        this.setScroll(scrollState);
                        this.isEventsRendered = false;
                    }
                },
                // Renders the events onto the view.
                renderEvents: function (events) {
                    // subclasses should implement
                },
                // Removes event elements from the view.
                unrenderEvents: function () {
                    // subclasses should implement
                },
                // Signals that all events have been rendered
                triggerEventRender: function () {
                    this.renderedEventSegEach(function (seg) {
                        this.trigger('eventAfterRender', seg.event, seg.event, seg.el);
                    });
                    this.trigger('eventAfterAllRender');
                },
                // Signals that all event elements are about to be removed
                triggerEventUnrender: function () {
                    this.renderedEventSegEach(function (seg) {
                        this.trigger('eventDestroy', seg.event, seg.event, seg.el);
                    });
                },
                // Given an event and the default element used for rendering, returns the element that should actually be used.
                // Basically runs events and elements through the eventRender hook.
                resolveEventEl: function (event, el) {
                    var custom = this.trigger('eventRender', event, event, el);

                    if (custom === false) { // means don't render at all
                        el = null;
                    } else if (custom && custom !== true) {
                        el = $(custom);
                    }

                    return el;
                },
                // Hides all rendered event segments linked to the given event
                showEvent: function (event) {
                    this.renderedEventSegEach(function (seg) {
                        seg.el.css('visibility', '');
                    }, event);
                },
                // Shows all rendered event segments linked to the given event
                hideEvent: function (event) {
                    this.renderedEventSegEach(function (seg) {
                        seg.el.css('visibility', 'hidden');
                    }, event);
                },
                // Iterates through event segments that have been rendered (have an el). Goes through all by default.
                // If the optional `event` argument is specified, only iterates through segments linked to that event.
                // The `this` value of the callback function will be the view.
                renderedEventSegEach: function (func, event) {
                    var segs = this.getEventSegs();
                    var i;

                    for (i = 0; i < segs.length; i++) {
                        if (!event || segs[i].event._id === event._id) {
                            if (segs[i].el) {
                                func.call(this, segs[i]);
                            }
                        }
                    }
                },
                // Retrieves all the rendered segment objects for the view
                getEventSegs: function () {
                    // subclasses must implement
                    return [];
                },
                /* Event Drag-n-Drop
                 ------------------------------------------------------------------------------------------------------------------*/


                // Computes if the given event is allowed to be dragged by the user
                isEventDraggable: function (event) {
                    var source = event.source || {};

                    return firstDefined(
                            event.startEditable,
                            source.startEditable,
                            this.opt('eventStartEditable'),
                            event.editable,
                            source.editable,
                            this.opt('editable')
                            );
                },
                // Must be called when an event in the view is dropped onto new location.
                // `dropLocation` is an object that contains the new zoned start/end/allDay values for the event.
                reportEventDrop: function (event, dropLocation, largeUnit, el, ev) {
                    var calendar = this.calendar;
                    var mutateResult = calendar.mutateEvent(event, dropLocation, largeUnit);
                    var undoFunc = function () {
                        mutateResult.undo();
                        calendar.reportEventChange();
                    };

                    this.triggerEventDrop(event, mutateResult.dateDelta, undoFunc, el, ev);
                    calendar.reportEventChange(); // will rerender events
                },
                // Triggers event-drop handlers that have subscribed via the API
                triggerEventDrop: function (event, dateDelta, undoFunc, el, ev) {
                    this.trigger('eventDrop', el[0], event, dateDelta, undoFunc, ev, {}); // {} = jqui dummy
                },
                /* External Element Drag-n-Drop
                 ------------------------------------------------------------------------------------------------------------------*/


                // Must be called when an external element, via jQuery UI, has been dropped onto the calendar.
                // `meta` is the parsed data that has been embedded into the dragging event.
                // `dropLocation` is an object that contains the new zoned start/end/allDay values for the event.
                reportExternalDrop: function (meta, dropLocation, el, ev, ui) {
                    var eventProps = meta.eventProps;
                    var eventInput;
                    var event;

                    // Try to build an event object and render it. TODO: decouple the two
                    if (eventProps) {
                        eventInput = $.extend({}, eventProps, dropLocation);
                        event = this.calendar.renderEvent(eventInput, meta.stick)[0]; // renderEvent returns an array
                    }

                    this.triggerExternalDrop(event, dropLocation, el, ev, ui);
                },
                // Triggers external-drop handlers that have subscribed via the API
                triggerExternalDrop: function (event, dropLocation, el, ev, ui) {

                    // trigger 'drop' regardless of whether element represents an event
                    this.trigger('drop', el[0], dropLocation.start, ev, ui);

                    if (event) {
                        this.trigger('eventReceive', null, event); // signal an external event landed
                    }
                },
                /* Drag-n-Drop Rendering (for both events and external elements)
                 ------------------------------------------------------------------------------------------------------------------*/


                // Renders a visual indication of a event or external-element drag over the given drop zone.
                // If an external-element, seg will be `null`.
                // Must return elements used for any mock events.
                renderDrag: function (dropLocation, seg) {
                    // subclasses must implement
                },
                // Unrenders a visual indication of an event or external-element being dragged.
                unrenderDrag: function () {
                    // subclasses must implement
                },
                /* Event Resizing
                 ------------------------------------------------------------------------------------------------------------------*/


                // Computes if the given event is allowed to be resized from its starting edge
                isEventResizableFromStart: function (event) {
                    return this.opt('eventResizableFromStart') && this.isEventResizable(event);
                },
                // Computes if the given event is allowed to be resized from its ending edge
                isEventResizableFromEnd: function (event) {
                    return this.isEventResizable(event);
                },
                // Computes if the given event is allowed to be resized by the user at all
                isEventResizable: function (event) {
                    var source = event.source || {};

                    return firstDefined(
                            event.durationEditable,
                            source.durationEditable,
                            this.opt('eventDurationEditable'),
                            event.editable,
                            source.editable,
                            this.opt('editable')
                            );
                },
                // Must be called when an event in the view has been resized to a new length
                reportEventResize: function (event, resizeLocation, largeUnit, el, ev) {
                    var calendar = this.calendar;
                    var mutateResult = calendar.mutateEvent(event, resizeLocation, largeUnit);
                    var undoFunc = function () {
                        mutateResult.undo();
                        calendar.reportEventChange();
                    };

                    this.triggerEventResize(event, mutateResult.durationDelta, undoFunc, el, ev);
                    calendar.reportEventChange(); // will rerender events
                },
                // Triggers event-resize handlers that have subscribed via the API
                triggerEventResize: function (event, durationDelta, undoFunc, el, ev) {
                    this.trigger('eventResize', el[0], event, durationDelta, undoFunc, ev, {}); // {} = jqui dummy
                },
                /* Selection (time range)
                 ------------------------------------------------------------------------------------------------------------------*/


                // Selects a date span on the view. `start` and `end` are both Moments.
                // `ev` is the native mouse event that begin the interaction.
                select: function (span, ev) {
                    this.unselect(ev);
                    this.renderSelection(span);
                    this.reportSelection(span, ev);
                },
                // Renders a visual indication of the selection
                renderSelection: function (span) {
                    // subclasses should implement
                },
                // Called when a new selection is made. Updates internal state and triggers handlers.
                reportSelection: function (span, ev) {
                    this.isSelected = true;
                    this.triggerSelect(span, ev);
                },
                // Triggers handlers to 'select'
                triggerSelect: function (span, ev) {
                    this.trigger(
                            'select',
                            null,
                            this.calendar.applyTimezone(span.start), // convert to calendar's tz for external API
                            this.calendar.applyTimezone(span.end), // "
                            ev
                            );
                },
                // Undoes a selection. updates in the internal state and triggers handlers.
                // `ev` is the native mouse event that began the interaction.
                unselect: function (ev) {
                    if (this.isSelected) {
                        this.isSelected = false;
                        if (this.destroySelection) {
                            this.destroySelection(); // TODO: deprecate
                        }
                        this.unrenderSelection();
                        this.trigger('unselect', null, ev);
                    }
                },
                // Unrenders a visual indication of selection
                unrenderSelection: function () {
                    // subclasses should implement
                },
                /* Event Selection
                 ------------------------------------------------------------------------------------------------------------------*/


                selectEvent: function (event) {
                    if (!this.selectedEvent || this.selectedEvent !== event) {
                        this.unselectEvent();
                        this.renderedEventSegEach(function (seg) {
                            seg.el.addClass('fc-selected');
                        }, event);
                        this.selectedEvent = event;
                    }
                },
                unselectEvent: function () {
                    if (this.selectedEvent) {
                        this.renderedEventSegEach(function (seg) {
                            seg.el.removeClass('fc-selected');
                        }, this.selectedEvent);
                        this.selectedEvent = null;
                    }
                },
                isEventSelected: function (event) {
                    // event references might change on refetchEvents(), while selectedEvent doesn't,
                    // so compare IDs
                    return this.selectedEvent && this.selectedEvent._id === event._id;
                },
                /* Mouse / Touch Unselecting (time range & event unselection)
                 ------------------------------------------------------------------------------------------------------------------*/
                // TODO: move consistently to down/start or up/end?
                // TODO: don't kill previous selection if touch scrolling


                handleDocumentMousedown: function (ev) {
                    if (isPrimaryMouseButton(ev)) {
                        this.processUnselect(ev);
                    }
                },
                processUnselect: function (ev) {
                    this.processRangeUnselect(ev);
                    this.processEventUnselect(ev);
                },
                processRangeUnselect: function (ev) {
                    var ignore;

                    // is there a time-range selection?
                    if (this.isSelected && this.opt('unselectAuto')) {
                        // only unselect if the clicked element is not identical to or inside of an 'unselectCancel' element
                        ignore = this.opt('unselectCancel');
                        if (!ignore || !$(ev.target).closest(ignore).length) {
                            this.unselect(ev);
                        }
                    }
                },
                processEventUnselect: function (ev) {
                    if (this.selectedEvent) {
                        if (!$(ev.target).closest('.fc-selected').length) {
                            this.unselectEvent();
                        }
                    }
                },
                /* Day Click
                 ------------------------------------------------------------------------------------------------------------------*/


                // Triggers handlers to 'dayClick'
                // Span has start/end of the clicked area. Only the start is useful.
                triggerDayClick: function (span, dayEl, ev) {
                    this.trigger(
                            'dayClick',
                            dayEl,
                            this.calendar.applyTimezone(span.start), // convert to calendar's timezone for external API
                            ev
                            );
                },
                /* Date Utils
                 ------------------------------------------------------------------------------------------------------------------*/


                // Initializes internal variables related to calculating hidden days-of-week
                initHiddenDays: function () {
                    var hiddenDays = this.opt('hiddenDays') || []; // array of day-of-week indices that are hidden
                    var isHiddenDayHash = []; // is the day-of-week hidden? (hash with day-of-week-index -> bool)
                    var dayCnt = 0;
                    var i;

                    if (this.opt('weekends') === false) {
                        hiddenDays.push(0, 6); // 0=sunday, 6=saturday
                    }

                    for (i = 0; i < 7; i++) {
                        if (
                                !(isHiddenDayHash[i] = $.inArray(i, hiddenDays) !== -1)
                                ) {
                            dayCnt++;
                        }
                    }

                    if (!dayCnt) {
                        throw 'invalid hiddenDays'; // all days were hidden? bad.
                    }

                    this.isHiddenDayHash = isHiddenDayHash;
                },
                // Is the current day hidden?
                // `day` is a day-of-week index (0-6), or a Moment
                isHiddenDay: function (day) {
                    if (moment.isMoment(day)) {
                        day = day.day();
                    }
                    return this.isHiddenDayHash[day];
                },
                // Incrementing the current day until it is no longer a hidden day, returning a copy.
                // If the initial value of `date` is not a hidden day, don't do anything.
                // Pass `isExclusive` as `true` if you are dealing with an end date.
                // `inc` defaults to `1` (increment one day forward each time)
                skipHiddenDays: function (date, inc, isExclusive) {
                    var out = date.clone();
                    inc = inc || 1;
                    while (
                            this.isHiddenDayHash[(out.day() + (isExclusive ? inc : 0) + 7) % 7]
                            ) {
                        out.add(inc, 'days');
                    }
                    return out;
                },
                // Returns the date range of the full days the given range visually appears to occupy.
                // Returns a new range object.
                computeDayRange: function (range) {
                    var startDay = range.start.clone().stripTime(); // the beginning of the day the range starts
                    var end = range.end;
                    var endDay = null;
                    var endTimeMS;

                    if (end) {
                        endDay = end.clone().stripTime(); // the beginning of the day the range exclusively ends
                        endTimeMS = +end.time(); // # of milliseconds into `endDay`

                        // If the end time is actually inclusively part of the next day and is equal to or
                        // beyond the next day threshold, adjust the end to be the exclusive end of `endDay`.
                        // Otherwise, leaving it as inclusive will cause it to exclude `endDay`.
                        if (endTimeMS && endTimeMS >= this.nextDayThreshold) {
                            endDay.add(1, 'days');
                        }
                    }

                    // If no end was specified, or if it is within `startDay` but not past nextDayThreshold,
                    // assign the default duration of one day.
                    if (!end || endDay <= startDay) {
                        endDay = startDay.clone().add(1, 'days');
                    }

                    return {start: startDay, end: endDay};
                },
                // Does the given event visually appear to occupy more than one day?
                isMultiDayEvent: function (event) {
                    var range = this.computeDayRange(event); // event is range-ish

                    return range.end.diff(range.start, 'days') > 1;
                }

            });

            ;
            ;

            /*
             Embodies a div that has potential scrollbars
             */
            var Scroller = FC.Scroller = Class.extend({
                el: null, // the guaranteed outer element
                scrollEl: null, // the element with the scrollbars
                overflowX: null,
                overflowY: null,
                constructor: function (options) {
                    options = options || {};
                    this.overflowX = options.overflowX || options.overflow || 'auto';
                    this.overflowY = options.overflowY || options.overflow || 'auto';
                },
                render: function () {
                    this.el = this.renderEl();
                    this.applyOverflow();
                },
                renderEl: function () {
                    return (this.scrollEl = $('<div class="fc-scroller"></div>'));
                },
                // sets to natural height, unlocks overflow
                clear: function () {
                    this.setHeight('auto');
                    this.applyOverflow();
                },
                destroy: function () {
                    this.el.remove();
                },
                // Overflow
                // -----------------------------------------------------------------------------------------------------------------


                applyOverflow: function () {
                    this.scrollEl.css({
                        'overflow-x': this.overflowX,
                        'overflow-y': this.overflowY
                    });
                },
                // Causes any 'auto' overflow values to resolves to 'scroll' or 'hidden'.
                // Useful for preserving scrollbar widths regardless of future resizes.
                // Can pass in scrollbarWidths for optimization.
                lockOverflow: function (scrollbarWidths) {
                    var overflowX = this.overflowX;
                    var overflowY = this.overflowY;

                    scrollbarWidths = scrollbarWidths || this.getScrollbarWidths();

                    if (overflowX === 'auto') {
                        overflowX = (
                                scrollbarWidths.top || scrollbarWidths.bottom || // horizontal scrollbars?
                                // OR scrolling pane with massless scrollbars?
                                this.scrollEl[0].scrollWidth - 1 > this.scrollEl[0].clientWidth
                                // subtract 1 because of IE off-by-one issue
                                ) ? 'scroll' : 'hidden';
                    }

                    if (overflowY === 'auto') {
                        overflowY = (
                                scrollbarWidths.left || scrollbarWidths.right || // vertical scrollbars?
                                // OR scrolling pane with massless scrollbars?
                                this.scrollEl[0].scrollHeight - 1 > this.scrollEl[0].clientHeight
                                // subtract 1 because of IE off-by-one issue
                                ) ? 'scroll' : 'hidden';
                    }

                    this.scrollEl.css({'overflow-x': overflowX, 'overflow-y': overflowY});
                },
                // Getters / Setters
                // -----------------------------------------------------------------------------------------------------------------


                setHeight: function (height) {
                    this.scrollEl.height(height);
                },
                getScrollTop: function () {
                    return this.scrollEl.scrollTop();
                },
                setScrollTop: function (top) {
                    this.scrollEl.scrollTop(top);
                },
                getClientWidth: function () {
                    return this.scrollEl[0].clientWidth;
                },
                getClientHeight: function () {
                    return this.scrollEl[0].clientHeight;
                },
                getScrollbarWidths: function () {
                    return getScrollbarWidths(this.scrollEl);
                }

            });

            ;
            ;

            var Calendar = FC.Calendar = Class.extend({
                dirDefaults: null, // option defaults related to LTR or RTL
                langDefaults: null, // option defaults related to current locale
                overrides: null, // option overrides given to the fullCalendar constructor
                options: null, // all defaults combined with overrides
                viewSpecCache: null, // cache of view definitions
                view: null, // current View object
                header: null,
                loadingLevel: 0, // number of simultaneous loading tasks


                // a lot of this class' OOP logic is scoped within this constructor function,
                // but in the future, write individual methods on the prototype.
                constructor: Calendar_constructor,
                // Subclasses can override this for initialization logic after the constructor has been called
                initialize: function () {
                },
                // Initializes `this.options` and other important options-related objects
                initOptions: function (overrides) {
                    var lang, langDefaults;
                    var isRTL, dirDefaults;

                    // converts legacy options into non-legacy ones.
                    // in the future, when this is removed, don't use `overrides` reference. make a copy.
                    overrides = massageOverrides(overrides);

                    lang = overrides.lang;
                    langDefaults = langOptionHash[lang];
                    if (!langDefaults) {
                        lang = Calendar.defaults.lang;
                        langDefaults = langOptionHash[lang] || {};
                    }

                    isRTL = firstDefined(
                            overrides.isRTL,
                            langDefaults.isRTL,
                            Calendar.defaults.isRTL
                            );
                    dirDefaults = isRTL ? Calendar.rtlDefaults : {};

                    this.dirDefaults = dirDefaults;
                    this.langDefaults = langDefaults;
                    this.overrides = overrides;
                    this.options = mergeOptions([// merge defaults and overrides. lowest to highest precedence
                        Calendar.defaults, // global defaults
                        dirDefaults,
                        langDefaults,
                        overrides
                    ]);
                    populateInstanceComputableOptions(this.options);

                    this.viewSpecCache = {}; // somewhat unrelated
                },
                // Gets information about how to create a view. Will use a cache.
                getViewSpec: function (viewType) {
                    var cache = this.viewSpecCache;

                    return cache[viewType] || (cache[viewType] = this.buildViewSpec(viewType));
                },
                // Given a duration singular unit, like "week" or "day", finds a matching view spec.
                // Preference is given to views that have corresponding buttons.
                getUnitViewSpec: function (unit) {
                    var viewTypes;
                    var i;
                    var spec;

                    if ($.inArray(unit, intervalUnits) != -1) {

                        // put views that have buttons first. there will be duplicates, but oh well
                        viewTypes = this.header.getViewsWithButtons();
                        $.each(FC.views, function (viewType) { // all views
                            viewTypes.push(viewType);
                        });

                        for (i = 0; i < viewTypes.length; i++) {
                            spec = this.getViewSpec(viewTypes[i]);
                            if (spec) {
                                if (spec.singleUnit == unit) {
                                    return spec;
                                }
                            }
                        }
                    }
                },
                // Builds an object with information on how to create a given view
                buildViewSpec: function (requestedViewType) {
                    var viewOverrides = this.overrides.views || {};
                    var specChain = []; // for the view. lowest to highest priority
                    var defaultsChain = []; // for the view. lowest to highest priority
                    var overridesChain = []; // for the view. lowest to highest priority
                    var viewType = requestedViewType;
                    var spec; // for the view
                    var overrides; // for the view
                    var duration;
                    var unit;

                    // iterate from the specific view definition to a more general one until we hit an actual View class
                    while (viewType) {
                        spec = fcViews[viewType];
                        overrides = viewOverrides[viewType];
                        viewType = null; // clear. might repopulate for another iteration

                        if (typeof spec === 'function') { // TODO: deprecate
                            spec = {'class': spec};
                        }

                        if (spec) {
                            specChain.unshift(spec);
                            defaultsChain.unshift(spec.defaults || {});
                            duration = duration || spec.duration;
                            viewType = viewType || spec.type;
                        }

                        if (overrides) {
                            overridesChain.unshift(overrides); // view-specific option hashes have options at zero-level
                            duration = duration || overrides.duration;
                            viewType = viewType || overrides.type;
                        }
                    }

                    spec = mergeProps(specChain);
                    spec.type = requestedViewType;
                    if (!spec['class']) {
                        return false;
                    }

                    if (duration) {
                        duration = moment.duration(duration);
                        if (duration.valueOf()) { // valid?
                            spec.duration = duration;
                            unit = computeIntervalUnit(duration);

                            // view is a single-unit duration, like "week" or "day"
                            // incorporate options for this. lowest priority
                            if (duration.as(unit) === 1) {
                                spec.singleUnit = unit;
                                overridesChain.unshift(viewOverrides[unit] || {});
                            }
                        }
                    }

                    spec.defaults = mergeOptions(defaultsChain);
                    spec.overrides = mergeOptions(overridesChain);

                    this.buildViewSpecOptions(spec);
                    this.buildViewSpecButtonText(spec, requestedViewType);

                    return spec;
                },
                // Builds and assigns a view spec's options object from its already-assigned defaults and overrides
                buildViewSpecOptions: function (spec) {
                    spec.options = mergeOptions([// lowest to highest priority
                        Calendar.defaults, // global defaults
                        spec.defaults, // view's defaults (from ViewSubclass.defaults)
                        this.dirDefaults,
                        this.langDefaults, // locale and dir take precedence over view's defaults!
                        this.overrides, // calendar's overrides (options given to constructor)
                        spec.overrides // view's overrides (view-specific options)
                    ]);
                    populateInstanceComputableOptions(spec.options);
                },
                // Computes and assigns a view spec's buttonText-related options
                buildViewSpecButtonText: function (spec, requestedViewType) {

                    // given an options object with a possible `buttonText` hash, lookup the buttonText for the
                    // requested view, falling back to a generic unit entry like "week" or "day"
                    function queryButtonText(options) {
                        var buttonText = options.buttonText || {};
                        return buttonText[requestedViewType] ||
                                (spec.singleUnit ? buttonText[spec.singleUnit] : null);
                    }

                    // highest to lowest priority
                    spec.buttonTextOverride =
                            queryButtonText(this.overrides) || // constructor-specified buttonText lookup hash takes precedence
                            spec.overrides.buttonText; // `buttonText` for view-specific options is a string

                    // highest to lowest priority. mirrors buildViewSpecOptions
                    spec.buttonTextDefault =
                            queryButtonText(this.langDefaults) ||
                            queryButtonText(this.dirDefaults) ||
                            spec.defaults.buttonText || // a single string. from ViewSubclass.defaults
                            queryButtonText(Calendar.defaults) ||
                            (spec.duration ? this.humanizeDuration(spec.duration) : null) || // like "3 days"
                            requestedViewType; // fall back to given view name
                },
                // Given a view name for a custom view or a standard view, creates a ready-to-go View object
                instantiateView: function (viewType) {
                    var spec = this.getViewSpec(viewType);

                    return new spec['class'](this, viewType, spec.options, spec.duration);
                },
                // Returns a boolean about whether the view is okay to instantiate at some point
                isValidViewType: function (viewType) {
                    return Boolean(this.getViewSpec(viewType));
                },
                // Should be called when any type of async data fetching begins
                pushLoading: function () {
                    if (!(this.loadingLevel++)) {
                        this.trigger('loading', null, true, this.view);
                    }
                },
                // Should be called when any type of async data fetching completes
                popLoading: function () {
                    if (!(--this.loadingLevel)) {
                        this.trigger('loading', null, false, this.view);
                    }
                },
                // Given arguments to the select method in the API, returns a span (unzoned start/end and other info)
                buildSelectSpan: function (zonedStartInput, zonedEndInput) {
                    var start = this.moment(zonedStartInput).stripZone();
                    var end;

                    if (zonedEndInput) {
                        end = this.moment(zonedEndInput).stripZone();
                    } else if (start.hasTime()) {
                        end = start.clone().add(this.defaultTimedEventDuration);
                    } else {
                        end = start.clone().add(this.defaultAllDayEventDuration);
                    }

                    return {start: start, end: end};
                }

            });


            Calendar.mixin(EmitterMixin);


            function Calendar_constructor(element, overrides) {
                var t = this;


                t.initOptions(overrides || {});
                var options = this.options;


                // Exports
                // -----------------------------------------------------------------------------------

                t.render = render;
                t.destroy = destroy;
                t.refetchEvents = refetchEvents;
                t.refetchEventSources = refetchEventSources;
                t.reportEvents = reportEvents;
                t.reportEventChange = reportEventChange;
                t.rerenderEvents = renderEvents; // `renderEvents` serves as a rerender. an API method
                t.changeView = renderView; // `renderView` will switch to another view
                t.select = select;
                t.unselect = unselect;
                t.prev = prev;
                t.next = next;
                t.prevYear = prevYear;
                t.nextYear = nextYear;
                t.today = today;
                t.gotoDate = gotoDate;
                t.incrementDate = incrementDate;
                t.zoomTo = zoomTo;
                t.getDate = getDate;
                t.getCalendar = getCalendar;
                t.getView = getView;
                t.option = option;
                t.trigger = trigger;



                // Language-data Internals
                // -----------------------------------------------------------------------------------
                // Apply overrides to the current language's data


                var localeData = createObject(// make a cheap copy
                        getMomentLocaleData(options.lang) // will fall back to en
                        );

                if (options.monthNames) {
                    localeData._months = options.monthNames;
                }
                if (options.monthNamesShort) {
                    localeData._monthsShort = options.monthNamesShort;
                }
                if (options.dayNames) {
                    localeData._weekdays = options.dayNames;
                }
                if (options.dayNamesShort) {
                    localeData._weekdaysShort = options.dayNamesShort;
                }
                if (options.firstDay != null) {
                    var _week = createObject(localeData._week); // _week: { dow: # }
                    _week.dow = options.firstDay;
                    localeData._week = _week;
                }

                // assign a normalized value, to be used by our .week() moment extension
                localeData._fullCalendar_weekCalc = (function (weekCalc) {
                    if (typeof weekCalc === 'function') {
                        return weekCalc;
                    } else if (weekCalc === 'local') {
                        return weekCalc;
                    } else if (weekCalc === 'iso' || weekCalc === 'ISO') {
                        return 'ISO';
                    }
                })(options.weekNumberCalculation);



                // Calendar-specific Date Utilities
                // -----------------------------------------------------------------------------------


                t.defaultAllDayEventDuration = moment.duration(options.defaultAllDayEventDuration);
                t.defaultTimedEventDuration = moment.duration(options.defaultTimedEventDuration);


                // Builds a moment using the settings of the current calendar: timezone and language.
                // Accepts anything the vanilla moment() constructor accepts.
                t.moment = function () {
                    var mom;

                    if (options.timezone === 'local') {
                        mom = FC.moment.apply(null, arguments);

                        // Force the moment to be local, because FC.moment doesn't guarantee it.
                        if (mom.hasTime()) { // don't give ambiguously-timed moments a local zone
                            mom.local();
                        }
                    } else if (options.timezone === 'UTC') {
                        mom = FC.moment.utc.apply(null, arguments); // process as UTC
                    } else {
                        mom = FC.moment.parseZone.apply(null, arguments); // let the input decide the zone
                    }

                    if ('_locale' in mom) { // moment 2.8 and above
                        mom._locale = localeData;
                    } else { // pre-moment-2.8
                        mom._lang = localeData;
                    }

                    return mom;
                };


                // Returns a boolean about whether or not the calendar knows how to calculate
                // the timezone offset of arbitrary dates in the current timezone.
                t.getIsAmbigTimezone = function () {
                    return options.timezone !== 'local' && options.timezone !== 'UTC';
                };


                // Returns a copy of the given date in the current timezone. Has no effect on dates without times.
                t.applyTimezone = function (date) {
                    if (!date.hasTime()) {
                        return date.clone();
                    }

                    var zonedDate = t.moment(date.toArray());
                    var timeAdjust = date.time() - zonedDate.time();
                    var adjustedZonedDate;

                    // Safari sometimes has problems with this coersion when near DST. Adjust if necessary. (bug #2396)
                    if (timeAdjust) { // is the time result different than expected?
                        adjustedZonedDate = zonedDate.clone().add(timeAdjust); // add milliseconds
                        if (date.time() - adjustedZonedDate.time() === 0) { // does it match perfectly now?
                            zonedDate = adjustedZonedDate;
                        }
                    }

                    return zonedDate;
                };


                // Returns a moment for the current date, as defined by the client's computer or from the `now` option.
                // Will return an moment with an ambiguous timezone.
                t.getNow = function () {
                    var now = options.now;
                    if (typeof now === 'function') {
                        now = now();
                    }
                    return t.moment(now).stripZone();
                };


                // Get an event's normalized end date. If not present, calculate it from the defaults.
                t.getEventEnd = function (event) {
                    if (event.end) {
                        return event.end.clone();
                    } else {
                        return t.getDefaultEventEnd(event.allDay, event.start);
                    }
                };


                // Given an event's allDay status and start date, return what its fallback end date should be.
                // TODO: rename to computeDefaultEventEnd
                t.getDefaultEventEnd = function (allDay, zonedStart) {
                    var end = zonedStart.clone();

                    if (allDay) {
                        end.stripTime().add(t.defaultAllDayEventDuration);
                    } else {
                        end.add(t.defaultTimedEventDuration);
                    }

                    if (t.getIsAmbigTimezone()) {
                        end.stripZone(); // we don't know what the tzo should be
                    }

                    return end;
                };


                // Produces a human-readable string for the given duration.
                // Side-effect: changes the locale of the given duration.
                t.humanizeDuration = function (duration) {
                    return (duration.locale || duration.lang).call(duration, options.lang) // works moment-pre-2.8
                            .humanize();
                };



                // Imports
                // -----------------------------------------------------------------------------------


                EventManager.call(t, options);
                var isFetchNeeded = t.isFetchNeeded;
                var fetchEvents = t.fetchEvents;
                var fetchEventSources = t.fetchEventSources;



                // Locals
                // -----------------------------------------------------------------------------------


                var _element = element[0];
                var header;
                var headerElement;
                var content;
                var tm; // for making theme classes
                var currentView; // NOTE: keep this in sync with this.view
                var viewsByType = {}; // holds all instantiated view instances, current or not
                var suggestedViewHeight;
                var windowResizeProxy; // wraps the windowResize function
                var ignoreWindowResize = 0;
                var events = [];
                var date; // unzoned



                // Main Rendering
                // -----------------------------------------------------------------------------------


                // compute the initial ambig-timezone date
                if (options.defaultDate != null) {
                    date = t.moment(options.defaultDate).stripZone();
                } else {
                    date = t.getNow(); // getNow already returns unzoned
                }


                function render() {
                    if (!content) {
                        initialRender();
                    } else if (elementVisible()) {
                        // mainly for the public API
                        calcSize();
                        renderView();
                    }
                }


                function initialRender() {
                    tm = options.theme ? 'ui' : 'fc';
                    element.addClass('fc');

                    if (options.isRTL) {
                        element.addClass('fc-rtl');
                    } else {
                        element.addClass('fc-ltr');
                    }

                    if (options.theme) {
                        element.addClass('ui-widget');
                    } else {
                        element.addClass('fc-unthemed');
                    }

                    content = $("<div class='fc-view-container'/>").prependTo(element);

                    header = t.header = new Header(t, options);
                    headerElement = header.render();
                    if (headerElement) {
                        element.prepend(headerElement);
                    }

                    renderView(options.defaultView);

                    if (options.handleWindowResize) {
                        windowResizeProxy = debounce(windowResize, options.windowResizeDelay); // prevents rapid calls
                        $(window).resize(windowResizeProxy);
                    }
                }


                function destroy() {

                    if (currentView) {
                        currentView.removeElement();

                        // NOTE: don't null-out currentView/t.view in case API methods are called after destroy.
                        // It is still the "current" view, just not rendered.
                    }

                    header.removeElement();
                    content.remove();
                    element.removeClass('fc fc-ltr fc-rtl fc-unthemed ui-widget');

                    if (windowResizeProxy) {
                        $(window).unbind('resize', windowResizeProxy);
                    }
                }


                function elementVisible() {
                    return element.is(':visible');
                }



                // View Rendering
                // -----------------------------------------------------------------------------------


                // Renders a view because of a date change, view-type change, or for the first time.
                // If not given a viewType, keep the current view but render different dates.
                function renderView(viewType) {
                    ignoreWindowResize++;

                    // if viewType is changing, remove the old view's rendering
                    if (currentView && viewType && currentView.type !== viewType) {
                        header.deactivateButton(currentView.type);
                        freezeContentHeight(); // prevent a scroll jump when view element is removed
                        currentView.removeElement();
                        currentView = t.view = null;
                    }

                    // if viewType changed, or the view was never created, create a fresh view
                    if (!currentView && viewType) {
                        currentView = t.view =
                                viewsByType[viewType] ||
                                (viewsByType[viewType] = t.instantiateView(viewType));

                        currentView.setElement(
                                $("<div class='fc-view fc-" + viewType + "-view' />").appendTo(content)
                                );
                        header.activateButton(viewType);
                    }

                    if (currentView) {

                        // in case the view should render a period of time that is completely hidden
                        date = currentView.massageCurrentDate(date);

                        // render or rerender the view
                        if (
                                !currentView.displaying ||
                                !date.isWithin(currentView.intervalStart, currentView.intervalEnd) // implicit date window change
                                ) {
                            if (elementVisible()) {

                                currentView.display(date); // will call freezeContentHeight
                                unfreezeContentHeight(); // immediately unfreeze regardless of whether display is async

                                // need to do this after View::render, so dates are calculated
                                updateHeaderTitle();
                                updateTodayButton();

                                getAndRenderEvents();
                            }
                        }
                    }

                    unfreezeContentHeight(); // undo any lone freezeContentHeight calls
                    ignoreWindowResize--;
                }



                // Resizing
                // -----------------------------------------------------------------------------------


                t.getSuggestedViewHeight = function () {
                    if (suggestedViewHeight === undefined) {
                        calcSize();
                    }
                    return suggestedViewHeight;
                };


                t.isHeightAuto = function () {
                    return options.contentHeight === 'auto' || options.height === 'auto';
                };


                function updateSize(shouldRecalc) {
                    if (elementVisible()) {

                        if (shouldRecalc) {
                            _calcSize();
                        }

                        ignoreWindowResize++;
                        currentView.updateSize(true); // isResize=true. will poll getSuggestedViewHeight() and isHeightAuto()
                        ignoreWindowResize--;

                        return true; // signal success
                    }
                }


                function calcSize() {
                    if (elementVisible()) {
                        _calcSize();
                    }
                }


                function _calcSize() { // assumes elementVisible
                    if (typeof options.contentHeight === 'number') { // exists and not 'auto'
                        suggestedViewHeight = options.contentHeight;
                    } else if (typeof options.height === 'number') { // exists and not 'auto'
                        suggestedViewHeight = options.height - (headerElement ? headerElement.outerHeight(true) : 0);
                    } else {
                        suggestedViewHeight = Math.round(content.width() / Math.max(options.aspectRatio, .5));
                    }
                }


                function windowResize(ev) {
                    if (
                            !ignoreWindowResize &&
                            ev.target === window && // so we don't process jqui "resize" events that have bubbled up
                            currentView.start // view has already been rendered
                            ) {
                        if (updateSize(true)) {
                            currentView.trigger('windowResize', _element);
                        }
                    }
                }



                /* Event Fetching/Rendering
                 -----------------------------------------------------------------------------*/
                // TODO: going forward, most of this stuff should be directly handled by the view


                function refetchEvents() { // can be called as an API method
                    fetchAndRenderEvents();
                }


                // TODO: move this into EventManager?
                function refetchEventSources(matchInputs) {
                    fetchEventSources(t.getEventSourcesByMatchArray(matchInputs));
                }


                function renderEvents() { // destroys old events if previously rendered
                    if (elementVisible()) {
                        freezeContentHeight();
                        currentView.displayEvents(events);
                        unfreezeContentHeight();
                    }
                }


                function getAndRenderEvents() {
                    if (!options.lazyFetching || isFetchNeeded(currentView.start, currentView.end)) {
                        fetchAndRenderEvents();
                    } else {
                        renderEvents();
                    }
                }


                function fetchAndRenderEvents() {
                    fetchEvents(currentView.start, currentView.end);
                    // ... will call reportEvents
                    // ... which will call renderEvents
                }


                // called when event data arrives
                function reportEvents(_events) {
                    events = _events;
                    renderEvents();
                }


                // called when a single event's data has been changed
                function reportEventChange() {
                    renderEvents();
                }



                /* Header Updating
                 -----------------------------------------------------------------------------*/


                function updateHeaderTitle() {
                    header.updateTitle(currentView.title);
                }


                function updateTodayButton() {
                    var now = t.getNow();
                    if (now.isWithin(currentView.intervalStart, currentView.intervalEnd)) {
                        header.disableButton('today');
                    } else {
                        header.enableButton('today');
                    }
                }



                /* Selection
                 -----------------------------------------------------------------------------*/


                // this public method receives start/end dates in any format, with any timezone
                function select(zonedStartInput, zonedEndInput) {
                    currentView.select(
                            t.buildSelectSpan.apply(t, arguments)
                            );
                }


                function unselect() { // safe to be called before renderView
                    if (currentView) {
                        currentView.unselect();
                    }
                }



                /* Date
                 -----------------------------------------------------------------------------*/


                function prev() {
                    date = currentView.computePrevDate(date);

                    renderView();
                }


                function next() {
                    date = currentView.computeNextDate(date);
                    renderView();
                }


                function prevYear() {
                    date.add(-1, 'years');
                    renderView();
                }


                function nextYear() {
                    date.add(1, 'years');
                    renderView();
                }


                function today() {
                    date = t.getNow();
                    renderView();
                }


                function gotoDate(zonedDateInput) {

                    date = t.moment(zonedDateInput).stripZone();
                    renderView();
                }

                function incrementDate(delta) {
                    date.add(moment.duration(delta));
                    renderView();
                }


                // Forces navigation to a view for the given date.
                // `viewType` can be a specific view name or a generic one like "week" or "day".
                function zoomTo(newDate, viewType) {
                    var spec;

                    viewType = viewType || 'day'; // day is default zoom
                    spec = t.getViewSpec(viewType) || t.getUnitViewSpec(viewType);

                    date = newDate.clone();
                    renderView(spec ? spec.type : null);
                }


                // for external API
                function getDate() {
                    return t.applyTimezone(date); // infuse the calendar's timezone
                }



                /* Height "Freezing"
                 -----------------------------------------------------------------------------*/
                // TODO: move this into the view

                t.freezeContentHeight = freezeContentHeight;
                t.unfreezeContentHeight = unfreezeContentHeight;


                function freezeContentHeight() {
                    content.css({
                        width: '100%',
                        height: content.height(),
                        overflow: 'hidden'
                    });
                }


                function unfreezeContentHeight() {
                    content.css({
                        width: '',
                        height: '',
                        overflow: ''
                    });
                }



                /* Misc
                 -----------------------------------------------------------------------------*/


                function getCalendar() {
                    return t;
                }


                function getView() {
                    return currentView;
                }


                function option(name, value) {
                    if (value === undefined) {
                        return options[name];
                    }
                    if (name == 'height' || name == 'contentHeight' || name == 'aspectRatio') {
                        options[name] = value;
                        updateSize(true); // true = allow recalculation of height
                    }
                }


                function trigger(name, thisObj) { // overrides the Emitter's trigger method :(
                    var args = Array.prototype.slice.call(arguments, 2);

                    thisObj = thisObj || _element;
                    this.triggerWith(name, thisObj, args); // Emitter's method

                    if (options[name]) {
                        return options[name].apply(thisObj, args);
                    }
                }

                t.initialize();
            }

            ;
            ;

            Calendar.defaults = {
                titleRangeSeparator: ' \u2013 ', // en dash
                monthYearFormat: 'MMMM YYYY', // required for en. other languages rely on datepicker computable option

                defaultTimedEventDuration: '02:00:00',
                defaultAllDayEventDuration: {days: 1},
                forceEventDuration: false,
                nextDayThreshold: '09:00:00', // 9am

                // display
                defaultView: 'month',
                aspectRatio: 1.35,
                header: {
                    left: 'title',
                    center: '',
                    right: 'today prev,next'
                },
                weekends: true,
                weekNumbers: false,
                weekNumberTitle: 'W',
                weekNumberCalculation: 'local',
                //editable: false,

                //nowIndicator: false,

                scrollTime: '06:00:00',
                // event ajax
                lazyFetching: true,
                startParam: 'start',
                endParam: 'end',
                timezoneParam: 'timezone',
                timezone: false,
                //allDayDefault: undefined,

                // locale
                isRTL: false,
                buttonText: {
                    prev: "prev",
                    next: "next",
                    prevYear: "prev year",
                    nextYear: "next year",
                    year: 'year', // TODO: locale files need to specify this
                    today: 'today',
                    month: 'month',
                    week: 'week',
                    day: 'day'
                },
                buttonIcons: {
                    prev: 'left-single-arrow',
                    next: 'right-single-arrow',
                    prevYear: 'left-double-arrow',
                    nextYear: 'right-double-arrow'
                },
                // jquery-ui theming
                theme: false,
                themeButtonIcons: {
                    prev: 'circle-triangle-w',
                    next: 'circle-triangle-e',
                    prevYear: 'seek-prev',
                    nextYear: 'seek-next'
                },
                //eventResizableFromStart: false,
                dragOpacity: .75,
                dragRevertDuration: 500,
                dragScroll: true,
                //selectable: false,
                unselectAuto: true,
                dropAccept: '*',
                eventOrder: 'title',
                eventLimit: false,
                eventLimitText: 'more',
                eventLimitClick: 'popover',
                dayPopoverFormat: 'LL',
                handleWindowResize: true,
                windowResizeDelay: 200, // milliseconds before an updateSize happens

                longPressDelay: 1000

            };


            Calendar.englishDefaults = {// used by lang.js
                dayPopoverFormat: 'dddd, MMMM D'
            };


            Calendar.rtlDefaults = {// right-to-left defaults
                header: {// TODO: smarter solution (first/center/last ?)
                    left: 'next,prev today',
                    center: '',
                    right: 'title'
                },
                buttonIcons: {
                    prev: 'right-single-arrow',
                    next: 'left-single-arrow',
                    prevYear: 'right-double-arrow',
                    nextYear: 'left-double-arrow'
                },
                themeButtonIcons: {
                    prev: 'circle-triangle-e',
                    next: 'circle-triangle-w',
                    nextYear: 'seek-prev',
                    prevYear: 'seek-next'
                }
            };

            ;
            ;

            var langOptionHash = FC.langs = {}; // initialize and expose


// TODO: document the structure and ordering of a FullCalendar lang file
// TODO: rename everything "lang" to "locale", like what the moment project did


// Initialize jQuery UI datepicker translations while using some of the translations
// Will set this as the default language for datepicker.
            FC.datepickerLang = function (langCode, dpLangCode, dpOptions) {

                // get the FullCalendar internal option hash for this language. create if necessary
                var fcOptions = langOptionHash[langCode] || (langOptionHash[langCode] = {});

                // transfer some simple options from datepicker to fc
                fcOptions.isRTL = dpOptions.isRTL;
                fcOptions.weekNumberTitle = dpOptions.weekHeader;

                // compute some more complex options from datepicker
                $.each(dpComputableOptions, function (name, func) {
                    fcOptions[name] = func(dpOptions);
                });

                // is jQuery UI Datepicker is on the page?
                if ($.datepicker) {

                    // Register the language data.
                    // FullCalendar and MomentJS use language codes like "pt-br" but Datepicker
                    // does it like "pt-BR" or if it doesn't have the language, maybe just "pt".
                    // Make an alias so the language can be referenced either way.
                    $.datepicker.regional[dpLangCode] =
                            $.datepicker.regional[langCode] = // alias
                            dpOptions;

                    // Alias 'en' to the default language data. Do this every time.
                    $.datepicker.regional.en = $.datepicker.regional[''];

                    // Set as Datepicker's global defaults.
                    $.datepicker.setDefaults(dpOptions);
                }
            };


// Sets FullCalendar-specific translations. Will set the language as the global default.
            FC.lang = function (langCode, newFcOptions) {
                var fcOptions;
                var momOptions;

                // get the FullCalendar internal option hash for this language. create if necessary
                fcOptions = langOptionHash[langCode] || (langOptionHash[langCode] = {});

                // provided new options for this language? merge them in
                if (newFcOptions) {
                    fcOptions = langOptionHash[langCode] = mergeOptions([fcOptions, newFcOptions]);
                }

                // compute language options that weren't defined.
                // always do this. newFcOptions can be undefined when initializing from i18n file,
                // so no way to tell if this is an initialization or a default-setting.
                momOptions = getMomentLocaleData(langCode); // will fall back to en
                $.each(momComputableOptions, function (name, func) {
                    if (fcOptions[name] == null) {
                        fcOptions[name] = func(momOptions, fcOptions);
                    }
                });

                // set it as the default language for FullCalendar
                Calendar.defaults.lang = langCode;
            };


// NOTE: can't guarantee any of these computations will run because not every language has datepicker
// configs, so make sure there are English fallbacks for these in the defaults file.
            var dpComputableOptions = {
                buttonText: function (dpOptions) {
                    return {
                        // the translations sometimes wrongly contain HTML entities
                        prev: stripHtmlEntities(dpOptions.prevText),
                        next: stripHtmlEntities(dpOptions.nextText),
                        today: stripHtmlEntities(dpOptions.currentText)
                    };
                },
                // Produces format strings like "MMMM YYYY" -> "September 2014"
                monthYearFormat: function (dpOptions) {
                    return dpOptions.showMonthAfterYear ?
                            'YYYY[' + dpOptions.yearSuffix + '] MMMM' :
                            'MMMM YYYY[' + dpOptions.yearSuffix + ']';
                }

            };

            var momComputableOptions = {
                // Produces format strings like "ddd M/D" -> "Fri 9/15"
                dayOfMonthFormat: function (momOptions, fcOptions) {
                    var format = momOptions.longDateFormat('l'); // for the format like "M/D/YYYY"

                    // strip the year off the edge, as well as other misc non-whitespace chars
                    format = format.replace(/^Y+[^\w\s]*|[^\w\s]*Y+$/g, '');

                    if (fcOptions.isRTL) {
                        format += ' ddd'; // for RTL, add day-of-week to end
                    } else {
                        format = 'ddd ' + format; // for LTR, add day-of-week to beginning
                    }
                    return format;
                },
                // Produces format strings like "h:mma" -> "6:00pm"
                mediumTimeFormat: function (momOptions) { // can't be called `timeFormat` because collides with option
                    return momOptions.longDateFormat('LT')
                            .replace(/\s*a$/i, 'a'); // convert AM/PM/am/pm to lowercase. remove any spaces beforehand
                },
                // Produces format strings like "h(:mm)a" -> "6pm" / "6:30pm"
                smallTimeFormat: function (momOptions) {
                    return momOptions.longDateFormat('LT')
                            .replace(':mm', '(:mm)')
                            .replace(/(\Wmm)$/, '($1)') // like above, but for foreign langs
                            .replace(/\s*a$/i, 'a'); // convert AM/PM/am/pm to lowercase. remove any spaces beforehand
                },
                // Produces format strings like "h(:mm)t" -> "6p" / "6:30p"
                extraSmallTimeFormat: function (momOptions) {
                    return momOptions.longDateFormat('LT')
                            .replace(':mm', '(:mm)')
                            .replace(/(\Wmm)$/, '($1)') // like above, but for foreign langs
                            .replace(/\s*a$/i, 't'); // convert to AM/PM/am/pm to lowercase one-letter. remove any spaces beforehand
                },
                // Produces format strings like "ha" / "H" -> "6pm" / "18"
                hourFormat: function (momOptions) {
                    return momOptions.longDateFormat('LT')
                            .replace(':mm', '')
                            .replace(/(\Wmm)$/, '') // like above, but for foreign langs
                            .replace(/\s*a$/i, 'a'); // convert AM/PM/am/pm to lowercase. remove any spaces beforehand
                },
                // Produces format strings like "h:mm" -> "6:30" (with no AM/PM)
                noMeridiemTimeFormat: function (momOptions) {
                    return momOptions.longDateFormat('LT')
                            .replace(/\s*a$/i, ''); // remove trailing AM/PM
                }

            };


// options that should be computed off live calendar options (considers override options)
// TODO: best place for this? related to lang?
// TODO: flipping text based on isRTL is a bad idea because the CSS `direction` might want to handle it
            var instanceComputableOptions = {
                // Produces format strings for results like "Mo 16"
                smallDayDateFormat: function (options) {
                    return options.isRTL ?
                            'D dd' :
                            'dd D';
                },
                // Produces format strings for results like "Wk 5"
                weekFormat: function (options) {
                    return options.isRTL ?
                            'w[ ' + options.weekNumberTitle + ']' :
                            '[' + options.weekNumberTitle + ' ]w';
                },
                // Produces format strings for results like "Wk5"
                smallWeekFormat: function (options) {
                    return options.isRTL ?
                            'w[' + options.weekNumberTitle + ']' :
                            '[' + options.weekNumberTitle + ']w';
                }

            };

            function populateInstanceComputableOptions(options) {
                $.each(instanceComputableOptions, function (name, func) {
                    if (options[name] == null) {
                        options[name] = func(options);
                    }
                });
            }


// Returns moment's internal locale data. If doesn't exist, returns English.
// Works with moment-pre-2.8
            function getMomentLocaleData(langCode) {
                var func = moment.localeData || moment.langData;
                return func.call(moment, langCode) ||
                        func.call(moment, 'en'); // the newer localData could return null, so fall back to en
            }


// Initialize English by forcing computation of moment-derived options.
// Also, sets it as the default.
            FC.lang('en', Calendar.englishDefaults);

            ;
            ;

            /* Top toolbar area with buttons and title
             ----------------------------------------------------------------------------------------------------------------------*/
// TODO: rename all header-related things to "toolbar"

            function Header(calendar, options) {
                var t = this;

                // exports
                t.render = render;
                t.removeElement = removeElement;
                t.updateTitle = updateTitle;
                t.activateButton = activateButton;
                t.deactivateButton = deactivateButton;
                t.disableButton = disableButton;
                t.enableButton = enableButton;
                t.getViewsWithButtons = getViewsWithButtons;

                // locals
                var el = $();
                var viewsWithButtons = [];
                var tm;


                function render() {
                    var sections = options.header;

                    tm = options.theme ? 'ui' : 'fc';

                    if (sections) {
                        el = $("<div class='fc-toolbar'/>")
                                .append(renderSection('left'))
                                .append(renderSection('right'))
                                .append(renderSection('center'))
                                .append('<div class="fc-clear"/>');

                        return el;
                    }
                }


                function removeElement() {
                    el.remove();
                    el = $();
                }


                function renderSection(position) {
                    var sectionEl = $('<div class="fc-' + position + '"/>');
                    var buttonStr = options.header[position];

                    if (buttonStr) {
                        $.each(buttonStr.split(' '), function (i) {
                            var groupChildren = $();
                            var isOnlyButtons = true;
                            var groupEl;
                            $.each(this.split(','), function (j, buttonName) {
                                var customButtonProps;
                                var viewSpec;
                                var buttonClick;
                                var overrideText; // text explicitly set by calendar's constructor options. overcomes icons
                                var defaultText;
                                var themeIcon;
                                var normalIcon;
                                var innerHtml;
                                var classes;
                                var button; // the element
                                if (buttonName == 'title') {
                                    groupChildren = groupChildren.add($('<h2 id="month_year">&nbsp;</h2>')); // we always want it to take up height

                                    isOnlyButtons = false;
                                } else {
                                    if ((customButtonProps = (calendar.options.customButtons || {})[buttonName])) {
                                        buttonClick = function (ev) {
                                            if (customButtonProps.click) {
                                                customButtonProps.click.call(button[0], ev);
                                            }
                                        };
                                        overrideText = ''; // icons will override text
                                        defaultText = customButtonProps.text;
                                    } else if ((viewSpec = calendar.getViewSpec(buttonName))) {
                                        buttonClick = function () {
                                            calendar.changeView(buttonName);
                                        };
                                        viewsWithButtons.push(buttonName);
                                        overrideText = viewSpec.buttonTextOverride;
                                        defaultText = viewSpec.buttonTextDefault;
                                    } else if (calendar[buttonName]) { // a calendar method
                                        buttonClick = function () {
                                            calendar[buttonName]();
                                        };
                                        overrideText = (calendar.overrides.buttonText || {})[buttonName];
                                        defaultText = options.buttonText[buttonName]; // everything else is considered default
                                    }

                                    if (buttonClick) {

                                        themeIcon =
                                                customButtonProps ?
                                                customButtonProps.themeIcon :
                                                options.themeButtonIcons[buttonName];

                                        normalIcon =
                                                customButtonProps ?
                                                customButtonProps.icon :
                                                options.buttonIcons[buttonName];

                                        if (overrideText) {
                                            innerHtml = htmlEscape(overrideText);
                                        } else if (themeIcon && options.theme) {
                                            innerHtml = "<span class='ui-icon ui-icon-" + themeIcon + "'></span>";
                                        } else if (normalIcon && !options.theme) {
                                            innerHtml = "<span class='fc-icon fc-icon-" + normalIcon + "'></span>";
                                        } else {
                                            innerHtml = htmlEscape(defaultText);
                                        }
                                        classes = [
                                            'fc-' + buttonName + '-button',
                                            tm + '-button',
                                            tm + '-state-default'
                                        ];

                                        button = $(// type="button" so that it doesn't submit a form
                                                '<button type="button" class="' + classes.join(' ') + '">' +
                                                innerHtml +
                                                '</button>'
                                                )
                                                .click(function (ev) {
                                                    // don't process clicks for disabled buttons
                                                    if (!button.hasClass(tm + '-state-disabled')) {

                                                        buttonClick(ev);

                                                        // after the click action, if the button becomes the "active" tab, or disabled,
                                                        // it should never have a hover class, so remove it now.
                                                        if (
                                                                button.hasClass(tm + '-state-active') ||
                                                                button.hasClass(tm + '-state-disabled')
                                                                ) {
                                                            button.removeClass(tm + '-state-hover');
                                                        }
                                                    }
                                                })
                                                .mousedown(function () {
                                                    // the *down* effect (mouse pressed in).
                                                    // only on buttons that are not the "active" tab, or disabled
                                                    button
                                                            .not('.' + tm + '-state-active')
                                                            .not('.' + tm + '-state-disabled')
                                                            .addClass(tm + '-state-down');
                                                })
                                                .mouseup(function () {
                                                    // undo the *down* effect
                                                    button.removeClass(tm + '-state-down');
                                                })
                                                .hover(
                                                        function () {
                                                            // the *hover* effect.
                                                            // only on buttons that are not the "active" tab, or disabled
                                                            button
                                                                    .not('.' + tm + '-state-active')
                                                                    .not('.' + tm + '-state-disabled')
                                                                    .addClass(tm + '-state-hover');
                                                        },
                                                        function () {
                                                            // undo the *hover* effect
                                                            button
                                                                    .removeClass(tm + '-state-hover')
                                                                    .removeClass(tm + '-state-down'); // if mouseleave happens before mouseup
                                                        }
                                                );
                                        if (buttonName == 'prev') {

                                            var selectHtml = '';
                                            var i = 0;
                                            selectHtml += "<span class='fc-dateSelect '>";


                                            // 循环年份
                                            selectHtml += "<select name='fcs_date_year' id='fcs_date_year' class='input-sm'>";
                                            for (i = 2016; i <= 2100; i++) {
                                                selectHtml += "<option value='" + i + "'>" + $.trim(i + "年") + "</option>";
                                            }
                                            selectHtml += "</select>";
                         
                                            selectHtml += "</select>";
                                            selectHtml += "</span>";
                                            groupChildren = groupChildren.add($(selectHtml));
                                        }
                                        
                                        groupChildren = groupChildren.add(button);

                                        if (buttonName == 'prev') {

                                            var selectmonthHtml = '';
                                            var i = 0;
                                            selectmonthHtml += "<div class='fc-dateSelect'>";

                                            // 循环月份
                                            selectmonthHtml += "<select name='fcs_date_month' id='fcs_date_month' class='input-sm'>";
                                            var monthDigitCN = ['一', '二', '三', '四', '五', '六', '七', '八', '九', '十', '十一', '十二'];
                                            for (i = 0; i <= 11; i++) {

                                                selectmonthHtml += "<option value='" + i + "'>" + $.trim(monthDigitCN[i] + "月") + "</option>";
                                            }
                                            selectmonthHtml += "</select>";
                                            selectmonthHtml += "</div>";
                                            groupChildren = groupChildren.add($(selectmonthHtml));
                                        }

                                    }
                                }
                            });

                            if (isOnlyButtons) {
                                groupChildren
                                        .first().addClass(tm + '-corner-left').end()
                                        .last().addClass(tm + '-corner-right').end();
                            }

                            if (groupChildren.length > 1) {
                                groupEl = $('<div/>');
                                if (isOnlyButtons) {
                                    groupEl.addClass('fc-button-group');
                                }
                                groupEl.append(groupChildren);
                                sectionEl.append(groupEl);
                            } else {
                                sectionEl.append(groupChildren); // 1 or 0 children
                            }
                        });
                    }

                    return sectionEl;
                }

//更新标题时候的动作，同时选中当前月份
                function updateTitle(text) {
                    el.find('h2').text(text);

                    var shtm = text.split(" ");
                    if (shtm && shtm.length > 1) {
                        $("#fcs_date_month").find("option").filter(function () {
                            return ($(this).text() == $.trim(shtm[1]));
                        }).prop('selected', true);
                        $("#fcs_date_year").find("option").filter(function () {
                            return ($(this).text() == $.trim(shtm[0]));
                        }).prop('selected', true);
                    }
                }


                function activateButton(buttonName) {
                    el.find('.fc-' + buttonName + '-button')
                            .addClass(tm + '-state-active');

                }


                function deactivateButton(buttonName) {
                    el.find('.fc-' + buttonName + '-button')
                            .removeClass(tm + '-state-active');
                }


                function disableButton(buttonName) {
                    el.find('.fc-' + buttonName + '-button')
                            .prop('disabled', true)
                            .addClass(tm + '-state-disabled');
                }


                function enableButton(buttonName) {
                    el.find('.fc-' + buttonName + '-button')
                            .prop('disabled', false)
                            .removeClass(tm + '-state-disabled');
                }


                function getViewsWithButtons() {
                    return viewsWithButtons;
                }

            }

            ;
            ;

            FC.sourceNormalizers = [];
            FC.sourceFetchers = [];

            var ajaxDefaults = {
                dataType: 'json',
                cache: false
            };

            var eventGUID = 1;


            function EventManager(options) { // assumed to be a calendar
                var t = this;


                // exports
                t.isFetchNeeded = isFetchNeeded;
                t.fetchEvents = fetchEvents;
                t.fetchEventSources = fetchEventSources;
                t.getEventSources = getEventSources;
                t.getEventSourceById = getEventSourceById;
                t.getEventSourcesByMatchArray = getEventSourcesByMatchArray;
                t.getEventSourcesByMatch = getEventSourcesByMatch;
                t.addEventSource = addEventSource;
                t.removeEventSource = removeEventSource;
                t.removeEventSources = removeEventSources;
                t.updateEvent = updateEvent;
                t.renderEvent = renderEvent;
                t.removeEvents = removeEvents;
                t.clientEvents = clientEvents;
                t.mutateEvent = mutateEvent;
                t.normalizeEventDates = normalizeEventDates;
                t.normalizeEventTimes = normalizeEventTimes;


                // imports
                var reportEvents = t.reportEvents;


                // locals
                var stickySource = {events: []};
                var sources = [stickySource];
                var rangeStart, rangeEnd;
                var pendingSourceCnt = 0; // outstanding fetch requests, max one per source
                var cache = []; // holds events that have already been expanded


                $.each(
                        (options.events ? [options.events] : []).concat(options.eventSources || []),
                        function (i, sourceInput) {
                            var source = buildEventSource(sourceInput);
                            if (source) {
                                sources.push(source);
                            }
                        }
                );



                /* Fetching
                 -----------------------------------------------------------------------------*/


                // start and end are assumed to be unzoned
                function isFetchNeeded(start, end) {
                    return !rangeStart || // nothing has been fetched yet?
                            start < rangeStart || end > rangeEnd; // is part of the new range outside of the old range?
                }


                function fetchEvents(start, end) {
                    rangeStart = start;
                    rangeEnd = end;
                    fetchEventSources(sources, 'reset');
                }


                // expects an array of event source objects (the originals, not copies)
                // `specialFetchType` is an optimization parameter that affects purging of the event cache.
                function fetchEventSources(specificSources, specialFetchType) {
                    var i, source;

                    if (specialFetchType === 'reset') {
                        cache = [];
                    } else if (specialFetchType !== 'add') {
                        cache = excludeEventsBySources(cache, specificSources);
                    }

                    for (i = 0; i < specificSources.length; i++) {
                        source = specificSources[i];

                        // already-pending sources have already been accounted for in pendingSourceCnt
                        if (source._status !== 'pending') {
                            pendingSourceCnt++;
                        }

                        source._fetchId = (source._fetchId || 0) + 1;
                        source._status = 'pending';
                    }

                    for (i = 0; i < specificSources.length; i++) {
                        source = specificSources[i];

                        tryFetchEventSource(source, source._fetchId);
                    }
                }


                // fetches an event source and processes its result ONLY if it is still the current fetch.
                // caller is responsible for incrementing pendingSourceCnt first.
                function tryFetchEventSource(source, fetchId) {
                    _fetchEventSource(source, function (eventInputs) {
                        var isArraySource = $.isArray(source.events);
                        var i, eventInput;
                        var abstractEvent;

                        if (
                                // is this the source's most recent fetch?
                                // if not, rely on an upcoming fetch of this source to decrement pendingSourceCnt
                                fetchId === source._fetchId &&
                                // event source no longer valid?
                                source._status !== 'rejected'
                                ) {
                            source._status = 'resolved';

                            if (eventInputs) {
                                for (i = 0; i < eventInputs.length; i++) {
                                    eventInput = eventInputs[i];

                                    if (isArraySource) { // array sources have already been convert to Event Objects
                                        abstractEvent = eventInput;
                                    } else {
                                        abstractEvent = buildEventFromInput(eventInput, source);
                                    }

                                    if (abstractEvent) { // not false (an invalid event)
                                        cache.push.apply(
                                                cache,
                                                expandEvent(abstractEvent) // add individual expanded events to the cache
                                                );
                                    }
                                }
                            }

                            decrementPendingSourceCnt();
                        }
                    });
                }


                function rejectEventSource(source) {
                    var wasPending = source._status === 'pending';

                    source._status = 'rejected';

                    if (wasPending) {
                        decrementPendingSourceCnt();
                    }
                }


                function decrementPendingSourceCnt() {
                    pendingSourceCnt--;
                    if (!pendingSourceCnt) {
                        reportEvents(cache);
                    }
                }


                function _fetchEventSource(source, callback) {
                    var i;
                    var fetchers = FC.sourceFetchers;
                    var res;

                    for (i = 0; i < fetchers.length; i++) {
                        res = fetchers[i].call(
                                t, // this, the Calendar object
                                source,
                                rangeStart.clone(),
                                rangeEnd.clone(),
                                options.timezone,
                                callback
                                );

                        if (res === true) {
                            // the fetcher is in charge. made its own async request
                            return;
                        } else if (typeof res == 'object') {
                            // the fetcher returned a new source. process it
                            _fetchEventSource(res, callback);
                            return;
                        }
                    }

                    var events = source.events;
                    if (events) {
                        if ($.isFunction(events)) {
                            t.pushLoading();
                            events.call(
                                    t, // this, the Calendar object
                                    rangeStart.clone(),
                                    rangeEnd.clone(),
                                    options.timezone,
                                    function (events) {
                                        callback(events);
                                        t.popLoading();
                                    }
                            );
                        } else if ($.isArray(events)) {
                            callback(events);
                        } else {
                            callback();
                        }
                    } else {
                        var url = source.url;
                        if (url) {
                            var success = source.success;
                            var error = source.error;
                            var complete = source.complete;

                            // retrieve any outbound GET/POST $.ajax data from the options
                            var customData;
                            if ($.isFunction(source.data)) {
                                // supplied as a function that returns a key/value object
                                customData = source.data();
                            } else {
                                // supplied as a straight key/value object
                                customData = source.data;
                            }

                            // use a copy of the custom data so we can modify the parameters
                            // and not affect the passed-in object.
                            var data = $.extend({}, customData || {});

                            var startParam = firstDefined(source.startParam, options.startParam);
                            var endParam = firstDefined(source.endParam, options.endParam);
                            var timezoneParam = firstDefined(source.timezoneParam, options.timezoneParam);

                            if (startParam) {
                                data[startParam] = rangeStart.format();
                            }
                            if (endParam) {
                                data[endParam] = rangeEnd.format();
                            }
                            if (options.timezone && options.timezone != 'local') {
                                data[timezoneParam] = options.timezone;
                            }

                            t.pushLoading();
                            $.ajax($.extend({}, ajaxDefaults, source, {
                                data: data,
                                success: function (events) {
                                    events = events || [];
                                    var res = applyAll(success, this, arguments);
                                    if ($.isArray(res)) {
                                        events = res;
                                    }
                                    callback(events);
                                },
                                error: function () {
                                    applyAll(error, this, arguments);
                                    callback();
                                },
                                complete: function () {
                                    applyAll(complete, this, arguments);
                                    t.popLoading();
                                }
                            }));
                        } else {
                            callback();
                        }
                    }
                }



                /* Sources
                 -----------------------------------------------------------------------------*/


                function addEventSource(sourceInput) {
                    var source = buildEventSource(sourceInput);
                    if (source) {
                        sources.push(source);
                        fetchEventSources([source], 'add'); // will eventually call reportEvents
                    }
                }


                function buildEventSource(sourceInput) { // will return undefined if invalid source
                    var normalizers = FC.sourceNormalizers;
                    var source;
                    var i;

                    if ($.isFunction(sourceInput) || $.isArray(sourceInput)) {
                        source = {events: sourceInput};
                    } else if (typeof sourceInput === 'string') {
                        source = {url: sourceInput};
                    } else if (typeof sourceInput === 'object') {
                        source = $.extend({}, sourceInput); // shallow copy
                    }

                    if (source) {

                        // TODO: repeat code, same code for event classNames
                        if (source.className) {
                            if (typeof source.className === 'string') {
                                source.className = source.className.split(/\s+/);
                            }
                            // otherwise, assumed to be an array
                        } else {
                            source.className = [];
                        }

                        // for array sources, we convert to standard Event Objects up front
                        if ($.isArray(source.events)) {
                            source.origArray = source.events; // for removeEventSource
                            source.events = $.map(source.events, function (eventInput) {
                                return buildEventFromInput(eventInput, source);
                            });
                        }

                        for (i = 0; i < normalizers.length; i++) {
                            normalizers[i].call(t, source);
                        }

                        return source;
                    }
                }


                function removeEventSource(matchInput) {
                    removeSpecificEventSources(
                            getEventSourcesByMatch(matchInput)
                            );
                }


                // if called with no arguments, removes all.
                function removeEventSources(matchInputs) {
                    if (matchInputs == null) {
                        removeSpecificEventSources(sources, true); // isAll=true
                    } else {
                        removeSpecificEventSources(
                                getEventSourcesByMatchArray(matchInputs)
                                );
                    }
                }


                function removeSpecificEventSources(targetSources, isAll) {
                    var i;

                    // cancel pending requests
                    for (i = 0; i < targetSources.length; i++) {
                        rejectEventSource(targetSources[i]);
                    }

                    if (isAll) { // an optimization
                        sources = [];
                        cache = [];
                    } else {
                        // remove from persisted source list
                        sources = $.grep(sources, function (source) {
                            for (i = 0; i < targetSources.length; i++) {
                                if (source === targetSources[i]) {
                                    return false; // exclude
                                }
                            }
                            return true; // include
                        });

                        cache = excludeEventsBySources(cache, targetSources);
                    }

                    reportEvents(cache);
                }


                function getEventSources() {
                    return sources.slice(1); // returns a shallow copy of sources with stickySource removed
                }


                function getEventSourceById(id) {
                    return $.grep(sources, function (source) {
                        return source.id && source.id === id;
                    })[0];
                }


                // like getEventSourcesByMatch, but accepts multple match criteria (like multiple IDs)
                function getEventSourcesByMatchArray(matchInputs) {

                    // coerce into an array
                    if (!matchInputs) {
                        matchInputs = [];
                    } else if (!$.isArray(matchInputs)) {
                        matchInputs = [matchInputs];
                    }

                    var matchingSources = [];
                    var i;

                    // resolve raw inputs to real event source objects
                    for (i = 0; i < matchInputs.length; i++) {
                        matchingSources.push.apply(// append
                                matchingSources,
                                getEventSourcesByMatch(matchInputs[i])
                                );
                    }

                    return matchingSources;
                }


                // matchInput can either by a real event source object, an ID, or the function/URL for the source.
                // returns an array of matching source objects.
                function getEventSourcesByMatch(matchInput) {
                    var i, source;

                    // given an proper event source object
                    for (i = 0; i < sources.length; i++) {
                        source = sources[i];
                        if (source === matchInput) {
                            return [source];
                        }
                    }

                    // an ID match
                    source = getEventSourceById(matchInput);
                    if (source) {
                        return [source];
                    }

                    return $.grep(sources, function (source) {
                        return isSourcesEquivalent(matchInput, source);
                    });
                }


                function isSourcesEquivalent(source1, source2) {
                    return source1 && source2 && getSourcePrimitive(source1) == getSourcePrimitive(source2);
                }


                function getSourcePrimitive(source) {
                    return (
                            (typeof source === 'object') ? // a normalized event source?
                            (source.origArray || source.googleCalendarId || source.url || source.events) : // get the primitive
                            null
                            ) ||
                            source; // the given argument *is* the primitive
                }


                // util
                // returns a filtered array without events that are part of any of the given sources
                function excludeEventsBySources(specificEvents, specificSources) {
                    return $.grep(specificEvents, function (event) {
                        for (var i = 0; i < specificSources.length; i++) {
                            if (event.source === specificSources[i]) {
                                return false; // exclude
                            }
                        }
                        return true; // keep
                    });
                }



                /* Manipulation
                 -----------------------------------------------------------------------------*/


                // Only ever called from the externally-facing API
                function updateEvent(event) {

                    // massage start/end values, even if date string values
                    event.start = t.moment(event.start);
                    if (event.end) {
                        event.end = t.moment(event.end);
                    } else {
                        event.end = null;
                    }

                    mutateEvent(event, getMiscEventProps(event)); // will handle start/end/allDay normalization
                    reportEvents(cache); // reports event modifications (so we can redraw)
                }


                // Returns a hash of misc event properties that should be copied over to related events.
                function getMiscEventProps(event) {
                    var props = {};

                    $.each(event, function (name, val) {
                        if (isMiscEventPropName(name)) {
                            if (val !== undefined && isAtomic(val)) { // a defined non-object
                                props[name] = val;
                            }
                        }
                    });

                    return props;
                }

                // non-date-related, non-id-related, non-secret
                function isMiscEventPropName(name) {
                    return !/^_|^(id|allDay|start|end)$/.test(name);
                }


                // returns the expanded events that were created
                function renderEvent(eventInput, stick) {
                    var abstractEvent = buildEventFromInput(eventInput);
                    var events;
                    var i, event;

                    if (abstractEvent) { // not false (a valid input)
                        events = expandEvent(abstractEvent);

                        for (i = 0; i < events.length; i++) {
                            event = events[i];

                            if (!event.source) {
                                if (stick) {
                                    stickySource.events.push(event);
                                    event.source = stickySource;
                                }
                                cache.push(event);
                            }
                        }

                        reportEvents(cache);

                        return events;
                    }

                    return [];
                }


                function removeEvents(filter) {
                    var eventID;
                    var i;

                    if (filter == null) { // null or undefined. remove all events
                        filter = function () {
                            return true;
                        }; // will always match
                    } else if (!$.isFunction(filter)) { // an event ID
                        eventID = filter + '';
                        filter = function (event) {
                            return event._id == eventID;
                        };
                    }

                    // Purge event(s) from our local cache
                    cache = $.grep(cache, filter, true); // inverse=true

                    // Remove events from array sources.
                    // This works because they have been converted to official Event Objects up front.
                    // (and as a result, event._id has been calculated).
                    for (i = 0; i < sources.length; i++) {
                        if ($.isArray(sources[i].events)) {
                            sources[i].events = $.grep(sources[i].events, filter, true);
                        }
                    }

                    reportEvents(cache);
                }


                function clientEvents(filter) {
                    if ($.isFunction(filter)) {
                        return $.grep(cache, filter);
                    } else if (filter != null) { // not null, not undefined. an event ID
                        filter += '';
                        return $.grep(cache, function (e) {
                            return e._id == filter;
                        });
                    }
                    return cache; // else, return all
                }



                /* Event Normalization
                 -----------------------------------------------------------------------------*/


                // Given a raw object with key/value properties, returns an "abstract" Event object.
                // An "abstract" event is an event that, if recurring, will not have been expanded yet.
                // Will return `false` when input is invalid.
                // `source` is optional
                function buildEventFromInput(input, source) {
                    var out = {};
                    var start, end;
                    var allDay;

                    if (options.eventDataTransform) {
                        input = options.eventDataTransform(input);
                    }
                    if (source && source.eventDataTransform) {
                        input = source.eventDataTransform(input);
                    }

                    // Copy all properties over to the resulting object.
                    // The special-case properties will be copied over afterwards.
                    $.extend(out, input);

                    if (source) {
                        out.source = source;
                    }

                    out._id = input._id || (input.id === undefined ? '_fc' + eventGUID++ : input.id + '');

                    if (input.className) {
                        if (typeof input.className == 'string') {
                            out.className = input.className.split(/\s+/);
                        } else { // assumed to be an array
                            out.className = input.className;
                        }
                    } else {
                        out.className = [];
                    }

                    start = input.start || input.date; // "date" is an alias for "start"
                    end = input.end;

                    // parse as a time (Duration) if applicable
                    if (isTimeString(start)) {
                        start = moment.duration(start);
                    }
                    if (isTimeString(end)) {
                        end = moment.duration(end);
                    }

                    if (input.dow || moment.isDuration(start) || moment.isDuration(end)) {

                        // the event is "abstract" (recurring) so don't calculate exact start/end dates just yet
                        out.start = start ? moment.duration(start) : null; // will be a Duration or null
                        out.end = end ? moment.duration(end) : null; // will be a Duration or null
                        out._recurring = true; // our internal marker
                    } else {

                        if (start) {
                            start = t.moment(start);
                            if (!start.isValid()) {
                                return false;
                            }
                        }

                        if (end) {
                            end = t.moment(end);
                            if (!end.isValid()) {
                                end = null; // let defaults take over
                            }
                        }

                        allDay = input.allDay;
                        if (allDay === undefined) { // still undefined? fallback to default
                            allDay = firstDefined(
                                    source ? source.allDayDefault : undefined,
                                    options.allDayDefault
                                    );
                            // still undefined? normalizeEventDates will calculate it
                        }

                        assignDatesToEvent(start, end, allDay, out);
                    }

                    t.normalizeEvent(out); // hook for external use. a prototype method

                    return out;
                }


                // Normalizes and assigns the given dates to the given partially-formed event object.
                // NOTE: mutates the given start/end moments. does not make a copy.
                function assignDatesToEvent(start, end, allDay, event) {
                    event.start = start;
                    event.end = end;
                    event.allDay = allDay;
                    normalizeEventDates(event);
                    backupEventDates(event);
                }


                // Ensures proper values for allDay/start/end. Accepts an Event object, or a plain object with event-ish properties.
                // NOTE: Will modify the given object.
                function normalizeEventDates(eventProps) {

                    normalizeEventTimes(eventProps);

                    if (eventProps.end && !eventProps.end.isAfter(eventProps.start)) {
                        eventProps.end = null;
                    }

                    if (!eventProps.end) {
                        if (options.forceEventDuration) {
                            eventProps.end = t.getDefaultEventEnd(eventProps.allDay, eventProps.start);
                        } else {
                            eventProps.end = null;
                        }
                    }
                }


                // Ensures the allDay property exists and the timeliness of the start/end dates are consistent
                function normalizeEventTimes(eventProps) {
                    if (eventProps.allDay == null) {
                        eventProps.allDay = !(eventProps.start.hasTime() || (eventProps.end && eventProps.end.hasTime()));
                    }

                    if (eventProps.allDay) {
                        eventProps.start.stripTime();
                        if (eventProps.end) {
                            // TODO: consider nextDayThreshold here? If so, will require a lot of testing and adjustment
                            eventProps.end.stripTime();
                        }
                    } else {
                        if (!eventProps.start.hasTime()) {
                            eventProps.start = t.applyTimezone(eventProps.start.time(0)); // will assign a 00:00 time
                        }
                        if (eventProps.end && !eventProps.end.hasTime()) {
                            eventProps.end = t.applyTimezone(eventProps.end.time(0)); // will assign a 00:00 time
                        }
                    }
                }


                // If the given event is a recurring event, break it down into an array of individual instances.
                // If not a recurring event, return an array with the single original event.
                // If given a falsy input (probably because of a failed buildEventFromInput call), returns an empty array.
                // HACK: can override the recurring window by providing custom rangeStart/rangeEnd (for businessHours).
                function expandEvent(abstractEvent, _rangeStart, _rangeEnd) {
                    var events = [];
                    var dowHash;
                    var dow;
                    var i;
                    var date;
                    var startTime, endTime;
                    var start, end;
                    var event;

                    _rangeStart = _rangeStart || rangeStart;
                    _rangeEnd = _rangeEnd || rangeEnd;

                    if (abstractEvent) {
                        if (abstractEvent._recurring) {

                            // make a boolean hash as to whether the event occurs on each day-of-week
                            if ((dow = abstractEvent.dow)) {
                                dowHash = {};
                                for (i = 0; i < dow.length; i++) {
                                    dowHash[dow[i]] = true;
                                }
                            }

                            // iterate through every day in the current range
                            date = _rangeStart.clone().stripTime(); // holds the date of the current day
                            while (date.isBefore(_rangeEnd)) {

                                if (!dowHash || dowHash[date.day()]) { // if everyday, or this particular day-of-week

                                    startTime = abstractEvent.start; // the stored start and end properties are times (Durations)
                                    endTime = abstractEvent.end; // "
                                    start = date.clone();
                                    end = null;

                                    if (startTime) {
                                        start = start.time(startTime);
                                    }
                                    if (endTime) {
                                        end = date.clone().time(endTime);
                                    }

                                    event = $.extend({}, abstractEvent); // make a copy of the original
                                    assignDatesToEvent(
                                            start, end,
                                            !startTime && !endTime, // allDay?
                                            event
                                            );
                                    events.push(event);
                                }

                                date.add(1, 'days');
                            }
                        } else {
                            events.push(abstractEvent); // return the original event. will be a one-item array
                        }
                    }

                    return events;
                }



                /* Event Modification Math
                 -----------------------------------------------------------------------------------------*/


                // Modifies an event and all related events by applying the given properties.
                // Special date-diffing logic is used for manipulation of dates.
                // If `props` does not contain start/end dates, the updated values are assumed to be the event's current start/end.
                // All date comparisons are done against the event's pristine _start and _end dates.
                // Returns an object with delta information and a function to undo all operations.
                // For making computations in a granularity greater than day/time, specify largeUnit.
                // NOTE: The given `newProps` might be mutated for normalization purposes.
                function mutateEvent(event, newProps, largeUnit) {
                    var miscProps = {};
                    var oldProps;
                    var clearEnd;
                    var startDelta;
                    var endDelta;
                    var durationDelta;
                    var undoFunc;

                    // diffs the dates in the appropriate way, returning a duration
                    function diffDates(date1, date0) { // date1 - date0
                        if (largeUnit) {
                            return diffByUnit(date1, date0, largeUnit);
                        } else if (newProps.allDay) {
                            return diffDay(date1, date0);
                        } else {
                            return diffDayTime(date1, date0);
                        }
                    }

                    newProps = newProps || {};

                    // normalize new date-related properties
                    if (!newProps.start) {
                        newProps.start = event.start.clone();
                    }
                    if (newProps.end === undefined) {
                        newProps.end = event.end ? event.end.clone() : null;
                    }
                    if (newProps.allDay == null) { // is null or undefined?
                        newProps.allDay = event.allDay;
                    }
                    normalizeEventDates(newProps);

                    // create normalized versions of the original props to compare against
                    // need a real end value, for diffing
                    oldProps = {
                        start: event._start.clone(),
                        end: event._end ? event._end.clone() : t.getDefaultEventEnd(event._allDay, event._start),
                        allDay: newProps.allDay // normalize the dates in the same regard as the new properties
                    };
                    normalizeEventDates(oldProps);

                    // need to clear the end date if explicitly changed to null
                    clearEnd = event._end !== null && newProps.end === null;

                    // compute the delta for moving the start date
                    startDelta = diffDates(newProps.start, oldProps.start);

                    // compute the delta for moving the end date
                    if (newProps.end) {
                        endDelta = diffDates(newProps.end, oldProps.end);
                        durationDelta = endDelta.subtract(startDelta);
                    } else {
                        durationDelta = null;
                    }

                    // gather all non-date-related properties
                    $.each(newProps, function (name, val) {
                        if (isMiscEventPropName(name)) {
                            if (val !== undefined) {
                                miscProps[name] = val;
                            }
                        }
                    });

                    // apply the operations to the event and all related events
                    undoFunc = mutateEvents(
                            clientEvents(event._id), // get events with this ID
                            clearEnd,
                            newProps.allDay,
                            startDelta,
                            durationDelta,
                            miscProps
                            );

                    return {
                        dateDelta: startDelta,
                        durationDelta: durationDelta,
                        undo: undoFunc
                    };
                }


                // Modifies an array of events in the following ways (operations are in order):
                // - clear the event's `end`
                // - convert the event to allDay
                // - add `dateDelta` to the start and end
                // - add `durationDelta` to the event's duration
                // - assign `miscProps` to the event
                //
                // Returns a function that can be called to undo all the operations.
                //
                // TODO: don't use so many closures. possible memory issues when lots of events with same ID.
                //
                function mutateEvents(events, clearEnd, allDay, dateDelta, durationDelta, miscProps) {
                    var isAmbigTimezone = t.getIsAmbigTimezone();
                    var undoFunctions = [];

                    // normalize zero-length deltas to be null
                    if (dateDelta && !dateDelta.valueOf()) {
                        dateDelta = null;
                    }
                    if (durationDelta && !durationDelta.valueOf()) {
                        durationDelta = null;
                    }

                    $.each(events, function (i, event) {
                        var oldProps;
                        var newProps;

                        // build an object holding all the old values, both date-related and misc.
                        // for the undo function.
                        oldProps = {
                            start: event.start.clone(),
                            end: event.end ? event.end.clone() : null,
                            allDay: event.allDay
                        };
                        $.each(miscProps, function (name) {
                            oldProps[name] = event[name];
                        });

                        // new date-related properties. work off the original date snapshot.
                        // ok to use references because they will be thrown away when backupEventDates is called.
                        newProps = {
                            start: event._start,
                            end: event._end,
                            allDay: allDay // normalize the dates in the same regard as the new properties
                        };
                        normalizeEventDates(newProps); // massages start/end/allDay

                        // strip or ensure the end date
                        if (clearEnd) {
                            newProps.end = null;
                        } else if (durationDelta && !newProps.end) { // the duration translation requires an end date
                            newProps.end = t.getDefaultEventEnd(newProps.allDay, newProps.start);
                        }

                        if (dateDelta) {
                            newProps.start.add(dateDelta);
                            if (newProps.end) {
                                newProps.end.add(dateDelta);
                            }
                        }

                        if (durationDelta) {
                            newProps.end.add(durationDelta); // end already ensured above
                        }

                        // if the dates have changed, and we know it is impossible to recompute the
                        // timezone offsets, strip the zone.
                        if (
                                isAmbigTimezone &&
                                !newProps.allDay &&
                                (dateDelta || durationDelta)
                                ) {
                            newProps.start.stripZone();
                            if (newProps.end) {
                                newProps.end.stripZone();
                            }
                        }

                        $.extend(event, miscProps, newProps); // copy over misc props, then date-related props
                        backupEventDates(event); // regenerate internal _start/_end/_allDay

                        undoFunctions.push(function () {
                            $.extend(event, oldProps);
                            backupEventDates(event); // regenerate internal _start/_end/_allDay
                        });
                    });

                    return function () {
                        for (var i = 0; i < undoFunctions.length; i++) {
                            undoFunctions[i]();
                        }
                    };
                }


                /* Business Hours
                 -----------------------------------------------------------------------------------------*/

                t.getBusinessHoursEvents = getBusinessHoursEvents;


                // Returns an array of events as to when the business hours occur in the given view.
                // Abuse of our event system :(
                function getBusinessHoursEvents(wholeDay) {
                    var optionVal = options.businessHours;
                    var defaultVal = {
                        className: 'fc-nonbusiness',
                        start: '09:00',
                        end: '17:00',
                        dow: [1, 2, 3, 4, 5], // monday - friday
                        rendering: 'inverse-background'
                    };
                    var view = t.getView();
                    var eventInput;

                    if (optionVal) { // `true` (which means "use the defaults") or an override object
                        eventInput = $.extend(
                                {}, // copy to a new object in either case
                                defaultVal,
                                typeof optionVal === 'object' ? optionVal : {} // override the defaults
                        );
                    }

                    if (eventInput) {

                        // if a whole-day series is requested, clear the start/end times
                        if (wholeDay) {
                            eventInput.start = null;
                            eventInput.end = null;
                        }

                        return expandEvent(
                                buildEventFromInput(eventInput),
                                view.start,
                                view.end
                                );
                    }

                    return [];
                }


                /* Overlapping / Constraining
                 -----------------------------------------------------------------------------------------*/

                t.isEventSpanAllowed = isEventSpanAllowed;
                t.isExternalSpanAllowed = isExternalSpanAllowed;
                t.isSelectionSpanAllowed = isSelectionSpanAllowed;


                // Determines if the given event can be relocated to the given span (unzoned start/end with other misc data)
                function isEventSpanAllowed(span, event) {
                    var source = event.source || {};
                    var constraint = firstDefined(
                            event.constraint,
                            source.constraint,
                            options.eventConstraint
                            );
                    var overlap = firstDefined(
                            event.overlap,
                            source.overlap,
                            options.eventOverlap
                            );
                    return isSpanAllowed(span, constraint, overlap, event);
                }


                // Determines if an external event can be relocated to the given span (unzoned start/end with other misc data)
                function isExternalSpanAllowed(eventSpan, eventLocation, eventProps) {
                    var eventInput;
                    var event;

                    // note: very similar logic is in View's reportExternalDrop
                    if (eventProps) {
                        eventInput = $.extend({}, eventProps, eventLocation);
                        event = expandEvent(buildEventFromInput(eventInput))[0];
                    }

                    if (event) {
                        return isEventSpanAllowed(eventSpan, event);
                    } else { // treat it as a selection

                        return isSelectionSpanAllowed(eventSpan);
                    }
                }


                // Determines the given span (unzoned start/end with other misc data) can be selected.
                function isSelectionSpanAllowed(span) {
                    return isSpanAllowed(span, options.selectConstraint, options.selectOverlap);
                }


                // Returns true if the given span (caused by an event drop/resize or a selection) is allowed to exist
                // according to the constraint/overlap settings.
                // `event` is not required if checking a selection.
                function isSpanAllowed(span, constraint, overlap, event) {
                    var constraintEvents;
                    var anyContainment;
                    var peerEvents;
                    var i, peerEvent;
                    var peerOverlap;

                    // the range must be fully contained by at least one of produced constraint events
                    if (constraint != null) {

                        // not treated as an event! intermediate data structure
                        // TODO: use ranges in the future
                        constraintEvents = constraintToEvents(constraint);

                        anyContainment = false;
                        for (i = 0; i < constraintEvents.length; i++) {
                            if (eventContainsRange(constraintEvents[i], span)) {
                                anyContainment = true;
                                break;
                            }
                        }

                        if (!anyContainment) {
                            return false;
                        }
                    }

                    peerEvents = t.getPeerEvents(span, event);

                    for (i = 0; i < peerEvents.length; i++) {
                        peerEvent = peerEvents[i];

                        // there needs to be an actual intersection before disallowing anything
                        if (eventIntersectsRange(peerEvent, span)) {

                            // evaluate overlap for the given range and short-circuit if necessary
                            if (overlap === false) {
                                return false;
                            }
                            // if the event's overlap is a test function, pass the peer event in question as the first param
                            else if (typeof overlap === 'function' && !overlap(peerEvent, event)) {
                                return false;
                            }

                            // if we are computing if the given range is allowable for an event, consider the other event's
                            // EventObject-specific or Source-specific `overlap` property
                            if (event) {
                                peerOverlap = firstDefined(
                                        peerEvent.overlap,
                                        (peerEvent.source || {}).overlap
                                        // we already considered the global `eventOverlap`
                                        );
                                if (peerOverlap === false) {
                                    return false;
                                }
                                // if the peer event's overlap is a test function, pass the subject event as the first param
                                if (typeof peerOverlap === 'function' && !peerOverlap(event, peerEvent)) {
                                    return false;
                                }
                            }
                        }
                    }

                    return true;
                }


                // Given an event input from the API, produces an array of event objects. Possible event inputs:
                // 'businessHours'
                // An event ID (number or string)
                // An object with specific start/end dates or a recurring event (like what businessHours accepts)
                function constraintToEvents(constraintInput) {

                    if (constraintInput === 'businessHours') {
                        return getBusinessHoursEvents();
                    }

                    if (typeof constraintInput === 'object') {
                        return expandEvent(buildEventFromInput(constraintInput));
                    }

                    return clientEvents(constraintInput); // probably an ID
                }


                // Does the event's date range fully contain the given range?
                // start/end already assumed to have stripped zones :(
                function eventContainsRange(event, range) {
                    var eventStart = event.start.clone().stripZone();
                    var eventEnd = t.getEventEnd(event).stripZone();

                    return range.start >= eventStart && range.end <= eventEnd;
                }


                // Does the event's date range intersect with the given range?
                // start/end already assumed to have stripped zones :(
                function eventIntersectsRange(event, range) {
                    var eventStart = event.start.clone().stripZone();
                    var eventEnd = t.getEventEnd(event).stripZone();

                    return range.start < eventEnd && range.end > eventStart;
                }


                t.getEventCache = function () {
                    return cache;
                };

            }


// hook for external libs to manipulate event properties upon creation.
// should manipulate the event in-place.
            Calendar.prototype.normalizeEvent = function (event) {
            };


// Returns a list of events that the given event should be compared against when being considered for a move to
// the specified span. Attached to the Calendar's prototype because EventManager is a mixin for a Calendar.
            Calendar.prototype.getPeerEvents = function (span, event) {
                var cache = this.getEventCache();
                var peerEvents = [];
                var i, otherEvent;

                for (i = 0; i < cache.length; i++) {
                    otherEvent = cache[i];
                    if (
                            !event ||
                            event._id !== otherEvent._id // don't compare the event to itself or other related [repeating] events
                            ) {
                        peerEvents.push(otherEvent);
                    }
                }

                return peerEvents;
            };


// updates the "backup" properties, which are preserved in order to compute diffs later on.
            function backupEventDates(event) {
                event._allDay = event.allDay;
                event._start = event.start.clone();
                event._end = event.end ? event.end.clone() : null;
            }

            ;
            ;

            /* An abstract class for the "basic" views, as well as month view. Renders one or more rows of day cells.
             ----------------------------------------------------------------------------------------------------------------------*/
// It is a manager for a DayGrid subcomponent, which does most of the heavy lifting.
// It is responsible for managing width/height.

            var BasicView = FC.BasicView = View.extend({
                scroller: null,
                dayGridClass: DayGrid, // class the dayGrid will be instantiated from (overridable by subclasses)
                dayGrid: null, // the main subcomponent that does most of the heavy lifting

                dayNumbersVisible: false, // display day numbers on each day cell?
                weekNumbersVisible: false, // display week numbers along the side?

                weekNumberWidth: null, // width of all the week-number cells running down the side

                headContainerEl: null, // div that hold's the dayGrid's rendered date header
                headRowEl: null, // the fake row element of the day-of-week header


                initialize: function () {
                    this.dayGrid = this.instantiateDayGrid();

                    this.scroller = new Scroller({
                        overflowX: 'hidden',
                        overflowY: 'auto'
                    });
                },
                // Generates the DayGrid object this view needs. Draws from this.dayGridClass
                instantiateDayGrid: function () {
                    // generate a subclass on the fly with BasicView-specific behavior
                    // TODO: cache this subclass
                    var subclass = this.dayGridClass.extend(basicDayGridMethods);

                    return new subclass(this);
                },
                // Sets the display range and computes all necessary dates
                setRange: function (range) {
                    View.prototype.setRange.call(this, range); // call the super-method

                    this.dayGrid.breakOnWeeks = /year|month|week/.test(this.intervalUnit); // do before setRange
                    this.dayGrid.setRange(range);
                },
                // Compute the value to feed into setRange. Overrides superclass.
                computeRange: function (date) {
                    var range = View.prototype.computeRange.call(this, date); // get value from the super-method

                    // year and month views should be aligned with weeks. this is already done for week
                    if (/year|month/.test(range.intervalUnit)) {
                        range.start.startOf('week');
                        range.start = this.skipHiddenDays(range.start);

                        // make end-of-week if not already
                        if (range.end.weekday()) {
                            range.end.add(1, 'week').startOf('week');
                            range.end = this.skipHiddenDays(range.end, -1, true); // exclusively move backwards
                        }
                    }

                    return range;
                },
                // Renders the view into `this.el`, which should already be assigned
                renderDates: function () {

                    this.dayNumbersVisible = this.dayGrid.rowCnt > 1; // TODO: make grid responsible
                    this.weekNumbersVisible = this.opt('weekNumbers');
                    this.dayGrid.numbersVisible = this.dayNumbersVisible || this.weekNumbersVisible;

                    this.el.addClass('fc-basic-view').html(this.renderSkeletonHtml());
                    this.renderHead();

                    this.scroller.render();
                    var dayGridContainerEl = this.scroller.el.addClass('fc-day-grid-container');
                    var dayGridEl = $('<div class="fc-day-grid" />').appendTo(dayGridContainerEl);
                    this.el.find('.fc-body > tr > td').append(dayGridContainerEl);

                    this.dayGrid.setElement(dayGridEl);
                    this.dayGrid.renderDates(this.hasRigidRows());
                },
                // render the day-of-week headers
                renderHead: function () {
                    this.headContainerEl =
                            this.el.find('.fc-head-container')
                            .html(this.dayGrid.renderHeadHtml());
                    this.headRowEl = this.headContainerEl.find('.fc-row');
                },
                // Unrenders the content of the view. Since we haven't separated skeleton rendering from date rendering,
                // always completely kill the dayGrid's rendering.
                unrenderDates: function () {
                    this.dayGrid.unrenderDates();
                    this.dayGrid.removeElement();
                    this.scroller.destroy();
                },
                renderBusinessHours: function () {
                    this.dayGrid.renderBusinessHours();
                },
                // Builds the HTML skeleton for the view.
                // The day-grid component will render inside of a container defined by this HTML.
                renderSkeletonHtml: function () {
                    return '' +
                            '<table>' +
                            '<thead class="fc-head">' +
                            '<tr>' +
                            '<td class="fc-head-container ' + this.widgetHeaderClass + '"></td>' +
                            '</tr>' +
                            '</thead>' +
                            '<tbody class="fc-body">' +
                            '<tr>' +
                            '<td class="' + this.widgetContentClass + '"></td>' +
                            '</tr>' +
                            '</tbody>' +
                            '</table>';
                },
                // Generates an HTML attribute string for setting the width of the week number column, if it is known
                weekNumberStyleAttr: function () {
                    if (this.weekNumberWidth !== null) {
                        return 'style="width:' + this.weekNumberWidth + 'px"';
                    }
                    return '';
                },
                // Determines whether each row should have a constant height
                hasRigidRows: function () {
                    var eventLimit = this.opt('eventLimit');
                    return eventLimit && typeof eventLimit !== 'number';
                },
                /* Dimensions
                 ------------------------------------------------------------------------------------------------------------------*/


                // Refreshes the horizontal dimensions of the view
                updateWidth: function () {
                    if (this.weekNumbersVisible) {
                        // Make sure all week number cells running down the side have the same width.
                        // Record the width for cells created later.
                        this.weekNumberWidth = matchCellWidths(
                                this.el.find('.fc-week-number')
                                );
                    }
                },
                // Adjusts the vertical dimensions of the view to the specified values
                setHeight: function (totalHeight, isAuto) {
                    var eventLimit = this.opt('eventLimit');
                    var scrollerHeight;
                    var scrollbarWidths;

                    // reset all heights to be natural
                    this.scroller.clear();
                    uncompensateScroll(this.headRowEl);

                    this.dayGrid.removeSegPopover(); // kill the "more" popover if displayed

                    // is the event limit a constant level number?
                    if (eventLimit && typeof eventLimit === 'number') {
                        this.dayGrid.limitRows(eventLimit); // limit the levels first so the height can redistribute after
                    }

                    // distribute the height to the rows
                    // (totalHeight is a "recommended" value if isAuto)
                    scrollerHeight = this.computeScrollerHeight(totalHeight);
                    this.setGridHeight(scrollerHeight, isAuto);

                    // is the event limit dynamically calculated?
                    if (eventLimit && typeof eventLimit !== 'number') {
                        this.dayGrid.limitRows(eventLimit); // limit the levels after the grid's row heights have been set
                    }

                    if (!isAuto) { // should we force dimensions of the scroll container?

                        this.scroller.setHeight(scrollerHeight);
                        scrollbarWidths = this.scroller.getScrollbarWidths();

                        if (scrollbarWidths.left || scrollbarWidths.right) { // using scrollbars?

                            compensateScroll(this.headRowEl, scrollbarWidths);

                            // doing the scrollbar compensation might have created text overflow which created more height. redo
                            scrollerHeight = this.computeScrollerHeight(totalHeight);
                            this.scroller.setHeight(scrollerHeight);
                        }

                        // guarantees the same scrollbar widths
                        this.scroller.lockOverflow(scrollbarWidths);
                    }
                },
                // given a desired total height of the view, returns what the height of the scroller should be
                computeScrollerHeight: function (totalHeight) {
                    return totalHeight -
                            subtractInnerElHeight(this.el, this.scroller.el); // everything that's NOT the scroller
                },
                // Sets the height of just the DayGrid component in this view
                setGridHeight: function (height, isAuto) {
                    if (isAuto) {
                        undistributeHeight(this.dayGrid.rowEls); // let the rows be their natural height with no expanding
                    } else {
                        distributeHeight(this.dayGrid.rowEls, height, true); // true = compensate for height-hogging rows
                    }
                },
                /* Scroll
                 ------------------------------------------------------------------------------------------------------------------*/


                queryScroll: function () {
                    return this.scroller.getScrollTop();
                },
                setScroll: function (top) {
                    this.scroller.setScrollTop(top);
                },
                /* Hit Areas
                 ------------------------------------------------------------------------------------------------------------------*/
                // forward all hit-related method calls to dayGrid


                prepareHits: function () {
                    this.dayGrid.prepareHits();
                },
                releaseHits: function () {
                    this.dayGrid.releaseHits();
                },
                queryHit: function (left, top) {
                    return this.dayGrid.queryHit(left, top);
                },
                getHitSpan: function (hit) {
                    return this.dayGrid.getHitSpan(hit);
                },
                getHitEl: function (hit) {
                    return this.dayGrid.getHitEl(hit);
                },
                /* Events
                 ------------------------------------------------------------------------------------------------------------------*/


                // Renders the given events onto the view and populates the segments array
                renderEvents: function (events) {
                    this.dayGrid.renderEvents(events);

                    this.updateHeight(); // must compensate for events that overflow the row
                },
                // Retrieves all segment objects that are rendered in the view
                getEventSegs: function () {
                    return this.dayGrid.getEventSegs();
                },
                // Unrenders all event elements and clears internal segment data
                unrenderEvents: function () {
                    this.dayGrid.unrenderEvents();

                    // we DON'T need to call updateHeight() because:
                    // A) a renderEvents() call always happens after this, which will eventually call updateHeight()
                    // B) in IE8, this causes a flash whenever events are rerendered
                },
                /* Dragging (for both events and external elements)
                 ------------------------------------------------------------------------------------------------------------------*/


                // A returned value of `true` signals that a mock "helper" event has been rendered.
                renderDrag: function (dropLocation, seg) {
                    return this.dayGrid.renderDrag(dropLocation, seg);
                },
                unrenderDrag: function () {
                    this.dayGrid.unrenderDrag();
                },
                /* Selection
                 ------------------------------------------------------------------------------------------------------------------*/


                // Renders a visual indication of a selection
                renderSelection: function (span) {
                    this.dayGrid.renderSelection(span);
                },
                // Unrenders a visual indications of a selection
                unrenderSelection: function () {
                    this.dayGrid.unrenderSelection();
                }

            });


// Methods that will customize the rendering behavior of the BasicView's dayGrid
            var basicDayGridMethods = {
                // Generates the HTML that will go before the day-of week header cells
                renderHeadIntroHtml: function () {
                    var view = this.view;

                    if (view.weekNumbersVisible) {
                        return '' +
                                '<th class="fc-week-number ' + view.widgetHeaderClass + '" ' + view.weekNumberStyleAttr() + '>' +
                                '<span>' + // needed for matchCellWidths
                                htmlEscape(view.opt('weekNumberTitle')) +
                                '</span>' +
                                '</th>';
                    }

                    return '';
                },
                // Generates the HTML that will go before content-skeleton cells that display the day/week numbers
                renderNumberIntroHtml: function (row) {
                    var view = this.view;

                    if (view.weekNumbersVisible) {
                        return '' +
                                '<td class="fc-week-number" ' + view.weekNumberStyleAttr() + '>' +
                                '<span>' + // needed for matchCellWidths
                                this.getCellDate(row, 0).format('w') +
                                '</span>' +
                                '</td>';
                    }

                    return '';
                },
                // Generates the HTML that goes before the day bg cells for each day-row
                renderBgIntroHtml: function () {
                    var view = this.view;

                    if (view.weekNumbersVisible) {
                        return '<td class="fc-week-number ' + view.widgetContentClass + '" ' +
                                view.weekNumberStyleAttr() + '></td>';
                    }

                    return '';
                },
                // Generates the HTML that goes before every other type of row generated by DayGrid.
                // Affects helper-skeleton and highlight-skeleton rows.
                renderIntroHtml: function () {
                    var view = this.view;

                    if (view.weekNumbersVisible) {
                        return '<td class="fc-week-number" ' + view.weekNumberStyleAttr() + '></td>';
                    }

                    return '';
                }

            };

            ;
            ;

            /* A month view with day cells running in rows (one-per-week) and columns
             ----------------------------------------------------------------------------------------------------------------------*/

            var MonthView = FC.MonthView = BasicView.extend({
                // Produces information about what range to display
                computeRange: function (date) {
                    var range = BasicView.prototype.computeRange.call(this, date); // get value from super-method
                    var rowCnt;

                    // ensure 6 weeks
                    if (this.isFixedWeeks()) {
                        rowCnt = Math.ceil(range.end.diff(range.start, 'weeks', true)); // could be partial weeks due to hiddenDays
                        range.end.add(6 - rowCnt, 'weeks');
                    }

                    return range;
                },
                // Overrides the default BasicView behavior to have special multi-week auto-height logic
                setGridHeight: function (height, isAuto) {

                    isAuto = isAuto || this.opt('weekMode') === 'variable'; // LEGACY: weekMode is deprecated

                    // if auto, make the height of each row the height that it would be if there were 6 weeks
                    if (isAuto) {
                        height *= this.rowCnt / 6;
                    }

                    distributeHeight(this.dayGrid.rowEls, height, !isAuto); // if auto, don't compensate for height-hogging rows
                },
                isFixedWeeks: function () {
                    var weekMode = this.opt('weekMode'); // LEGACY: weekMode is deprecated
                    if (weekMode) {
                        return weekMode === 'fixed'; // if any other type of weekMode, assume NOT fixed
                    }

                    return this.opt('fixedWeekCount');
                }

            });

            ;
            ;

            fcViews.basic = {
                'class': BasicView
            };

            fcViews.basicDay = {
                type: 'basic',
                duration: {days: 1}
            };

            fcViews.basicWeek = {
                type: 'basic',
                duration: {weeks: 1}
            };

            fcViews.month = {
                'class': MonthView,
                duration: {months: 1}, // important for prev/next
                defaults: {
                    fixedWeekCount: true
                }
            };
            ;
            ;

            /* An abstract class for all agenda-related views. Displays one more columns with time slots running vertically.
             ----------------------------------------------------------------------------------------------------------------------*/
// Is a manager for the TimeGrid subcomponent and possibly the DayGrid subcomponent (if allDaySlot is on).
// Responsible for managing width/height.

            var AgendaView = FC.AgendaView = View.extend({
                scroller: null,
                timeGridClass: TimeGrid, // class used to instantiate the timeGrid. subclasses can override
                timeGrid: null, // the main time-grid subcomponent of this view

                dayGridClass: DayGrid, // class used to instantiate the dayGrid. subclasses can override
                dayGrid: null, // the "all-day" subcomponent. if all-day is turned off, this will be null

                axisWidth: null, // the width of the time axis running down the side

                headContainerEl: null, // div that hold's the timeGrid's rendered date header
                noScrollRowEls: null, // set of fake row elements that must compensate when scroller has scrollbars

                // when the time-grid isn't tall enough to occupy the given height, we render an <hr> underneath
                bottomRuleEl: null,
                initialize: function () {
                    this.timeGrid = this.instantiateTimeGrid();

                    if (this.opt('allDaySlot')) { // should we display the "all-day" area?
                        this.dayGrid = this.instantiateDayGrid(); // the all-day subcomponent of this view
                    }

                    this.scroller = new Scroller({
                        overflowX: 'hidden',
                        overflowY: 'auto'
                    });
                },
                // Instantiates the TimeGrid object this view needs. Draws from this.timeGridClass
                instantiateTimeGrid: function () {
                    var subclass = this.timeGridClass.extend(agendaTimeGridMethods);

                    return new subclass(this);
                },
                // Instantiates the DayGrid object this view might need. Draws from this.dayGridClass
                instantiateDayGrid: function () {
                    var subclass = this.dayGridClass.extend(agendaDayGridMethods);

                    return new subclass(this);
                },
                /* Rendering
                 ------------------------------------------------------------------------------------------------------------------*/


                // Sets the display range and computes all necessary dates
                setRange: function (range) {
                    View.prototype.setRange.call(this, range); // call the super-method

                    this.timeGrid.setRange(range);
                    if (this.dayGrid) {
                        this.dayGrid.setRange(range);
                    }
                },
                // Renders the view into `this.el`, which has already been assigned
                renderDates: function () {

                    this.el.addClass('fc-agenda-view').html(this.renderSkeletonHtml());
                    this.renderHead();

                    this.scroller.render();
                    var timeGridWrapEl = this.scroller.el.addClass('fc-time-grid-container');
                    var timeGridEl = $('<div class="fc-time-grid" />').appendTo(timeGridWrapEl);
                    this.el.find('.fc-body > tr > td').append(timeGridWrapEl);

                    this.timeGrid.setElement(timeGridEl);
                    this.timeGrid.renderDates();

                    // the <hr> that sometimes displays under the time-grid
                    this.bottomRuleEl = $('<hr class="fc-divider ' + this.widgetHeaderClass + '"/>')
                            .appendTo(this.timeGrid.el); // inject it into the time-grid

                    if (this.dayGrid) {
                        this.dayGrid.setElement(this.el.find('.fc-day-grid'));
                        this.dayGrid.renderDates();

                        // have the day-grid extend it's coordinate area over the <hr> dividing the two grids
                        this.dayGrid.bottomCoordPadding = this.dayGrid.el.next('hr').outerHeight();
                    }

                    this.noScrollRowEls = this.el.find('.fc-row:not(.fc-scroller *)'); // fake rows not within the scroller
                },
                // render the day-of-week headers
                renderHead: function () {
                    this.headContainerEl =
                            this.el.find('.fc-head-container')
                            .html(this.timeGrid.renderHeadHtml());
                },
                // Unrenders the content of the view. Since we haven't separated skeleton rendering from date rendering,
                // always completely kill each grid's rendering.
                unrenderDates: function () {
                    this.timeGrid.unrenderDates();
                    this.timeGrid.removeElement();

                    if (this.dayGrid) {
                        this.dayGrid.unrenderDates();
                        this.dayGrid.removeElement();
                    }

                    this.scroller.destroy();
                },
                // Builds the HTML skeleton for the view.
                // The day-grid and time-grid components will render inside containers defined by this HTML.
                renderSkeletonHtml: function () {
                    return '' +
                            '<table>' +
                            '<thead class="fc-head">' +
                            '<tr>' +
                            '<td class="fc-head-container ' + this.widgetHeaderClass + '"></td>' +
                            '</tr>' +
                            '</thead>' +
                            '<tbody class="fc-body">' +
                            '<tr>' +
                            '<td class="' + this.widgetContentClass + '">' +
                            (this.dayGrid ?
                                    '<div class="fc-day-grid"/>' +
                                    '<hr class="fc-divider ' + this.widgetHeaderClass + '"/>' :
                                    ''
                                    ) +
                            '</td>' +
                            '</tr>' +
                            '</tbody>' +
                            '</table>';
                },
                // Generates an HTML attribute string for setting the width of the axis, if it is known
                axisStyleAttr: function () {
                    if (this.axisWidth !== null) {
                        return 'style="width:' + this.axisWidth + 'px"';
                    }
                    return '';
                },
                /* Business Hours
                 ------------------------------------------------------------------------------------------------------------------*/


                renderBusinessHours: function () {
                    this.timeGrid.renderBusinessHours();

                    if (this.dayGrid) {
                        this.dayGrid.renderBusinessHours();
                    }
                },
                unrenderBusinessHours: function () {
                    this.timeGrid.unrenderBusinessHours();

                    if (this.dayGrid) {
                        this.dayGrid.unrenderBusinessHours();
                    }
                },
                /* Now Indicator
                 ------------------------------------------------------------------------------------------------------------------*/


                getNowIndicatorUnit: function () {
                    return this.timeGrid.getNowIndicatorUnit();
                },
                renderNowIndicator: function (date) {
                    this.timeGrid.renderNowIndicator(date);
                },
                unrenderNowIndicator: function () {
                    this.timeGrid.unrenderNowIndicator();
                },
                /* Dimensions
                 ------------------------------------------------------------------------------------------------------------------*/


                updateSize: function (isResize) {
                    this.timeGrid.updateSize(isResize);

                    View.prototype.updateSize.call(this, isResize); // call the super-method
                },
                // Refreshes the horizontal dimensions of the view
                updateWidth: function () {
                    // make all axis cells line up, and record the width so newly created axis cells will have it
                    this.axisWidth = matchCellWidths(this.el.find('.fc-axis'));
                },
                // Adjusts the vertical dimensions of the view to the specified values
                setHeight: function (totalHeight, isAuto) {
                    var eventLimit;
                    var scrollerHeight;
                    var scrollbarWidths;

                    // reset all dimensions back to the original state
                    this.bottomRuleEl.hide(); // .show() will be called later if this <hr> is necessary
                    this.scroller.clear(); // sets height to 'auto' and clears overflow
                    uncompensateScroll(this.noScrollRowEls);

                    // limit number of events in the all-day area
                    if (this.dayGrid) {
                        this.dayGrid.removeSegPopover(); // kill the "more" popover if displayed

                        eventLimit = this.opt('eventLimit');
                        if (eventLimit && typeof eventLimit !== 'number') {
                            eventLimit = AGENDA_ALL_DAY_EVENT_LIMIT; // make sure "auto" goes to a real number
                        }
                        if (eventLimit) {
                            this.dayGrid.limitRows(eventLimit);
                        }
                    }

                    if (!isAuto) { // should we force dimensions of the scroll container?

                        scrollerHeight = this.computeScrollerHeight(totalHeight);
                        this.scroller.setHeight(scrollerHeight);
                        scrollbarWidths = this.scroller.getScrollbarWidths();

                        if (scrollbarWidths.left || scrollbarWidths.right) { // using scrollbars?

                            // make the all-day and header rows lines up
                            compensateScroll(this.noScrollRowEls, scrollbarWidths);

                            // the scrollbar compensation might have changed text flow, which might affect height, so recalculate
                            // and reapply the desired height to the scroller.
                            scrollerHeight = this.computeScrollerHeight(totalHeight);
                            this.scroller.setHeight(scrollerHeight);
                        }

                        // guarantees the same scrollbar widths
                        this.scroller.lockOverflow(scrollbarWidths);

                        // if there's any space below the slats, show the horizontal rule.
                        // this won't cause any new overflow, because lockOverflow already called.
                        if (this.timeGrid.getTotalSlatHeight() < scrollerHeight) {
                            this.bottomRuleEl.show();
                        }
                    }
                },
                // given a desired total height of the view, returns what the height of the scroller should be
                computeScrollerHeight: function (totalHeight) {
                    return totalHeight -
                            subtractInnerElHeight(this.el, this.scroller.el); // everything that's NOT the scroller
                },
                /* Scroll
                 ------------------------------------------------------------------------------------------------------------------*/


                // Computes the initial pre-configured scroll state prior to allowing the user to change it
                computeInitialScroll: function () {
                    var scrollTime = moment.duration(this.opt('scrollTime'));
                    var top = this.timeGrid.computeTimeTop(scrollTime);

                    // zoom can give weird floating-point values. rather scroll a little bit further
                    top = Math.ceil(top);

                    if (top) {
                        top++; // to overcome top border that slots beyond the first have. looks better
                    }

                    return top;
                },
                queryScroll: function () {
                    return this.scroller.getScrollTop();
                },
                setScroll: function (top) {
                    this.scroller.setScrollTop(top);
                },
                /* Hit Areas
                 ------------------------------------------------------------------------------------------------------------------*/
                // forward all hit-related method calls to the grids (dayGrid might not be defined)


                prepareHits: function () {
                    this.timeGrid.prepareHits();
                    if (this.dayGrid) {
                        this.dayGrid.prepareHits();
                    }
                },
                releaseHits: function () {
                    this.timeGrid.releaseHits();
                    if (this.dayGrid) {
                        this.dayGrid.releaseHits();
                    }
                },
                queryHit: function (left, top) {
                    var hit = this.timeGrid.queryHit(left, top);

                    if (!hit && this.dayGrid) {
                        hit = this.dayGrid.queryHit(left, top);
                    }

                    return hit;
                },
                getHitSpan: function (hit) {
                    // TODO: hit.component is set as a hack to identify where the hit came from
                    return hit.component.getHitSpan(hit);
                },
                getHitEl: function (hit) {
                    // TODO: hit.component is set as a hack to identify where the hit came from
                    return hit.component.getHitEl(hit);
                },
                /* Events
                 ------------------------------------------------------------------------------------------------------------------*/


                // Renders events onto the view and populates the View's segment array
                renderEvents: function (events) {
                    var dayEvents = [];
                    var timedEvents = [];
                    var daySegs = [];
                    var timedSegs;
                    var i;

                    // separate the events into all-day and timed
                    for (i = 0; i < events.length; i++) {
                        if (events[i].allDay) {
                            dayEvents.push(events[i]);
                        } else {
                            timedEvents.push(events[i]);
                        }
                    }

                    // render the events in the subcomponents
                    timedSegs = this.timeGrid.renderEvents(timedEvents);
                    if (this.dayGrid) {
                        daySegs = this.dayGrid.renderEvents(dayEvents);
                    }

                    // the all-day area is flexible and might have a lot of events, so shift the height
                    this.updateHeight();
                },
                // Retrieves all segment objects that are rendered in the view
                getEventSegs: function () {
                    return this.timeGrid.getEventSegs().concat(
                            this.dayGrid ? this.dayGrid.getEventSegs() : []
                            );
                },
                // Unrenders all event elements and clears internal segment data
                unrenderEvents: function () {

                    // unrender the events in the subcomponents
                    this.timeGrid.unrenderEvents();
                    if (this.dayGrid) {
                        this.dayGrid.unrenderEvents();
                    }

                    // we DON'T need to call updateHeight() because:
                    // A) a renderEvents() call always happens after this, which will eventually call updateHeight()
                    // B) in IE8, this causes a flash whenever events are rerendered
                },
                /* Dragging (for events and external elements)
                 ------------------------------------------------------------------------------------------------------------------*/


                // A returned value of `true` signals that a mock "helper" event has been rendered.
                renderDrag: function (dropLocation, seg) {
                    if (dropLocation.start.hasTime()) {
                        return this.timeGrid.renderDrag(dropLocation, seg);
                    } else if (this.dayGrid) {
                        return this.dayGrid.renderDrag(dropLocation, seg);
                    }
                },
                unrenderDrag: function () {
                    this.timeGrid.unrenderDrag();
                    if (this.dayGrid) {
                        this.dayGrid.unrenderDrag();
                    }
                },
                /* Selection
                 ------------------------------------------------------------------------------------------------------------------*/


                // Renders a visual indication of a selection
                renderSelection: function (span) {
                    if (span.start.hasTime() || span.end.hasTime()) {
                        this.timeGrid.renderSelection(span);
                    } else if (this.dayGrid) {
                        this.dayGrid.renderSelection(span);
                    }
                },
                // Unrenders a visual indications of a selection
                unrenderSelection: function () {
                    this.timeGrid.unrenderSelection();
                    if (this.dayGrid) {
                        this.dayGrid.unrenderSelection();
                    }
                }

            });


// Methods that will customize the rendering behavior of the AgendaView's timeGrid
// TODO: move into TimeGrid
            var agendaTimeGridMethods = {
                // Generates the HTML that will go before the day-of week header cells
                renderHeadIntroHtml: function () {
                    var view = this.view;
                    var weekText;

                    if (view.opt('weekNumbers')) {
                        weekText = this.start.format(view.opt('smallWeekFormat'));

                        return '' +
                                '<th class="fc-axis fc-week-number ' + view.widgetHeaderClass + '" ' + view.axisStyleAttr() + '>' +
                                '<span>' + // needed for matchCellWidths
                                htmlEscape(weekText) +
                                '</span>' +
                                '</th>';
                    } else {
                        return '<th class="fc-axis ' + view.widgetHeaderClass + '" ' + view.axisStyleAttr() + '></th>';
                    }
                },
                // Generates the HTML that goes before the bg of the TimeGrid slot area. Long vertical column.
                renderBgIntroHtml: function () {
                    var view = this.view;

                    return '<td class="fc-axis ' + view.widgetContentClass + '" ' + view.axisStyleAttr() + '></td>';
                },
                // Generates the HTML that goes before all other types of cells.
                // Affects content-skeleton, helper-skeleton, highlight-skeleton for both the time-grid and day-grid.
                renderIntroHtml: function () {
                    var view = this.view;

                    return '<td class="fc-axis" ' + view.axisStyleAttr() + '></td>';
                }

            };


// Methods that will customize the rendering behavior of the AgendaView's dayGrid
            var agendaDayGridMethods = {
                // Generates the HTML that goes before the all-day cells
                renderBgIntroHtml: function () {
                    var view = this.view;

                    return '' +
                            '<td class="fc-axis ' + view.widgetContentClass + '" ' + view.axisStyleAttr() + '>' +
                            '<span>' + // needed for matchCellWidths
                            (view.opt('allDayHtml') || htmlEscape(view.opt('allDayText'))) +
                            '</span>' +
                            '</td>';
                },
                // Generates the HTML that goes before all other types of cells.
                // Affects content-skeleton, helper-skeleton, highlight-skeleton for both the time-grid and day-grid.
                renderIntroHtml: function () {
                    var view = this.view;

                    return '<td class="fc-axis" ' + view.axisStyleAttr() + '></td>';
                }

            };

            ;
            ;

            var AGENDA_ALL_DAY_EVENT_LIMIT = 5;

// potential nice values for the slot-duration and interval-duration
// from largest to smallest
            var AGENDA_STOCK_SUB_DURATIONS = [
                {hours: 1},
                {minutes: 30},
                {minutes: 15},
                {seconds: 30},
                {seconds: 15}
            ];

            fcViews.agenda = {
                'class': AgendaView,
                defaults: {
                    allDaySlot: true,
                    allDayText: 'all-day',
                    slotDuration: '00:30:00',
                    minTime: '00:00:00',
                    maxTime: '24:00:00',
                    slotEventOverlap: true // a bad name. confused with overlap/constraint system
                }
            };

            fcViews.agendaDay = {
                type: 'agenda',
                duration: {days: 1}
            };

            fcViews.agendaWeek = {
                type: 'agenda',
                duration: {weeks: 1}
            };
            ;
            ;

            return FC; // export for Node/CommonJS
        });